diff --git a/libraries/stdlib/wasm/src/org.w3c/org.khronos.webgl.kt b/libraries/stdlib/wasm/src/org.w3c/org.khronos.webgl.kt
index 664a0e86364..fa434a77cf0 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.khronos.webgl.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.khronos.webgl.kt
@@ -243,13 +243,17 @@ public external interface WebGLRenderingContextBase : JsAny {
     fun useProgram(program: WebGLProgram?)
     fun validateProgram(program: WebGLProgram?)
     fun vertexAttrib1f(index: Int, x: Float)
-    fun vertexAttrib1fv(index: Int, values: JsAny?)
+    fun vertexAttrib1fv(index: Int, values: Float32Array)
+    fun vertexAttrib1fv(index: Int, values: JsArray<JsNumber>)
     fun vertexAttrib2f(index: Int, x: Float, y: Float)
-    fun vertexAttrib2fv(index: Int, values: JsAny?)
+    fun vertexAttrib2fv(index: Int, values: Float32Array)
+    fun vertexAttrib2fv(index: Int, values: JsArray<JsNumber>)
     fun vertexAttrib3f(index: Int, x: Float, y: Float, z: Float)
-    fun vertexAttrib3fv(index: Int, values: JsAny?)
+    fun vertexAttrib3fv(index: Int, values: Float32Array)
+    fun vertexAttrib3fv(index: Int, values: JsArray<JsNumber>)
     fun vertexAttrib4f(index: Int, x: Float, y: Float, z: Float, w: Float)
-    fun vertexAttrib4fv(index: Int, values: JsAny?)
+    fun vertexAttrib4fv(index: Int, values: Float32Array)
+    fun vertexAttrib4fv(index: Int, values: JsArray<JsNumber>)
     fun vertexAttribPointer(index: Int, size: Int, type: Int, normalized: Boolean, stride: Int, offset: Int)
     fun viewport(x: Int, y: Int, width: Int, height: Int)
 
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.events.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.events.kt
index be76523340a..c2f83d5405e 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.events.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.events.kt
@@ -343,10 +343,18 @@ public external open class Event(type: String, eventInitDict: EventInit = define
  * Exposes the JavaScript [EventTarget](https://developer.mozilla.org/en/docs/Web/API/EventTarget) to Kotlin
  */
 public external abstract class EventTarget : JsAny {
-    fun addEventListener(type: String, callback: EventListener?, options: JsAny? = definedExternally)
-    fun addEventListener(type: String, callback: ((Event) -> Unit)?, options: JsAny? = definedExternally)
-    fun removeEventListener(type: String, callback: EventListener?, options: JsAny? = definedExternally)
-    fun removeEventListener(type: String, callback: ((Event) -> Unit)?, options: JsAny? = definedExternally)
+    fun addEventListener(type: String, callback: EventListener?, options: AddEventListenerOptions)
+    fun addEventListener(type: String, callback: ((Event) -> Unit)?, options: AddEventListenerOptions)
+    fun addEventListener(type: String, callback: EventListener?, options: Boolean)
+    fun addEventListener(type: String, callback: ((Event) -> Unit)?, options: Boolean)
+    fun addEventListener(type: String, callback: EventListener?)
+    fun addEventListener(type: String, callback: ((Event) -> Unit)?)
+    fun removeEventListener(type: String, callback: EventListener?, options: EventListenerOptions)
+    fun removeEventListener(type: String, callback: ((Event) -> Unit)?, options: EventListenerOptions)
+    fun removeEventListener(type: String, callback: EventListener?, options: Boolean)
+    fun removeEventListener(type: String, callback: ((Event) -> Unit)?, options: Boolean)
+    fun removeEventListener(type: String, callback: EventListener?)
+    fun removeEventListener(type: String, callback: ((Event) -> Unit)?)
     fun dispatchEvent(event: Event): Boolean
 }
 
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.kt
index 94fa40cff42..7bfd16430dc 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.kt
@@ -58,7 +58,9 @@ public external abstract class RadioNodeList : NodeList, UnionElementOrRadioNode
 public external abstract class HTMLOptionsCollection : HTMLCollection, JsAny {
     override var length: Int
     open var selectedIndex: Int
-    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: JsAny? = definedExternally)
+    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: HTMLElement)
+    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: Int)
+    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement)
     fun remove(index: Int)
 }
 
@@ -2034,7 +2036,9 @@ public external abstract class HTMLSelectElement : HTMLElement, ItemArrayLike<El
     open val validationMessage: String
     open val labels: NodeList
     fun namedItem(name: String): HTMLOptionElement?
-    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: JsAny? = definedExternally)
+    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: HTMLElement)
+    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: Int)
+    fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement)
     fun remove(index: Int)
     fun checkValidity(): Boolean
     fun reportValidity(): Boolean
@@ -2771,8 +2775,8 @@ public external interface CanvasImageSmoothing : JsAny {
 }
 
 public external interface CanvasFillStrokeStyles : JsAny {
-    var strokeStyle: JsAny?
-    var fillStyle: JsAny?
+    var strokeStyle: JsAny? /* String|CanvasGradient|CanvasPattern */
+    var fillStyle: JsAny? /* String|CanvasGradient|CanvasPattern */
     fun createLinearGradient(x0: Double, y0: Double, x1: Double, y1: Double): CanvasGradient
     fun createRadialGradient(x0: Double, y0: Double, r0: Double, x1: Double, y1: Double, r1: Double): CanvasGradient
     fun createPattern(image: CanvasImageSource, repetition: String): CanvasPattern?
@@ -3433,7 +3437,7 @@ public external interface GlobalEventHandlers : JsAny {
     var onended: ((Event) -> Unit)?
         get() = definedExternally
         set(value) = definedExternally
-    var onerror: ((JsAny?, String, Int, Int, JsAny?) -> JsAny?)?
+    var onerror: ((JsAny? /* Event|String */, String, Int, Int, JsAny?) -> JsAny?)?
         get() = definedExternally
         set(value) = definedExternally
     var onfocus: ((FocusEvent) -> Unit)?
@@ -3653,13 +3657,16 @@ public external interface WindowOrWorkerGlobalScope : JsAny {
     val caches: CacheStorage
     fun btoa(data: String): String
     fun atob(data: String): String
-    fun setTimeout(handler: JsAny?, timeout: Int = definedExternally, vararg arguments: JsAny?): Int
+    fun setTimeout(handler: String, timeout: Int = definedExternally, vararg arguments: JsAny?): Int
+    fun setTimeout(handler: () -> JsAny?, timeout: Int = definedExternally, vararg arguments: JsAny?): Int
     fun clearTimeout(handle: Int = definedExternally)
-    fun setInterval(handler: JsAny?, timeout: Int = definedExternally, vararg arguments: JsAny?): Int
+    fun setInterval(handler: String, timeout: Int = definedExternally, vararg arguments: JsAny?): Int
+    fun setInterval(handler: () -> JsAny?, timeout: Int = definedExternally, vararg arguments: JsAny?): Int
     fun clearInterval(handle: Int = definedExternally)
     fun createImageBitmap(image: ImageBitmapSource, options: ImageBitmapOptions = definedExternally): Promise<ImageBitmap>
     fun createImageBitmap(image: ImageBitmapSource, sx: Int, sy: Int, sw: Int, sh: Int, options: ImageBitmapOptions = definedExternally): Promise<ImageBitmap>
-    fun fetch(input: JsAny?, init: RequestInit = definedExternally): Promise<Response>
+    fun fetch(input: Request, init: RequestInit = definedExternally): Promise<Response>
+    fun fetch(input: String, init: RequestInit = definedExternally): Promise<Response>
 }
 
 /**
@@ -3672,7 +3679,8 @@ public external abstract class Navigator : NavigatorID, NavigatorLanguage, Navig
     open val serviceWorker: ServiceWorkerContainer
     fun requestMediaKeySystemAccess(keySystem: String, supportedConfigurations: JsArray<MediaKeySystemConfiguration>): Promise<MediaKeySystemAccess>
     fun getUserMedia(constraints: MediaStreamConstraints, successCallback: (MediaStream) -> Unit, errorCallback: (JsAny) -> Unit)
-    fun vibrate(pattern: JsAny?): Boolean
+    fun vibrate(pattern: Int): Boolean
+    fun vibrate(pattern: JsArray<JsNumber>): Boolean
 }
 
 /**
@@ -3894,7 +3902,7 @@ public fun EventSourceInit(withCredentials: Boolean? = false): EventSourceInit {
 /**
  * Exposes the JavaScript [WebSocket](https://developer.mozilla.org/en/docs/Web/API/WebSocket) to Kotlin
  */
-public external open class WebSocket(url: String, protocols: JsAny? = definedExternally) : EventTarget, JsAny {
+public external open class WebSocket(url: String, protocols: JsAny? /* String|JsArray<JsString> */ = definedExternally) : EventTarget, JsAny {
     open val url: String
     open val readyState: Short
     open val bufferedAmount: JsNumber
@@ -3985,7 +3993,7 @@ public external abstract class WorkerGlobalScope : EventTarget, WindowOrWorkerGl
     open val self: WorkerGlobalScope
     open val location: WorkerLocation
     open val navigator: WorkerNavigator
-    open var onerror: ((JsAny?, String, Int, Int, JsAny?) -> JsAny?)?
+    open var onerror: ((JsAny? /* Event|String */, String, Int, Int, JsAny?) -> JsAny?)?
     open var onlanguagechange: ((Event) -> Unit)?
     open var onoffline: ((Event) -> Unit)?
     open var ononline: ((Event) -> Unit)?
@@ -4439,8 +4447,10 @@ public external interface ParentNode : JsAny {
     val lastElementChild: Element?
         get() = definedExternally
     val childElementCount: Int
-    fun prepend(vararg nodes: JsAny?)
-    fun append(vararg nodes: JsAny?)
+    fun prepend(vararg nodes: Node)
+    fun prepend(vararg nodes: String)
+    fun append(vararg nodes: Node)
+    fun append(vararg nodes: String)
     fun querySelector(selectors: String): Element?
     fun querySelectorAll(selectors: String): NodeList
 }
@@ -4459,9 +4469,12 @@ public external interface NonDocumentTypeChildNode : JsAny {
  * Exposes the JavaScript [ChildNode](https://developer.mozilla.org/en/docs/Web/API/ChildNode) to Kotlin
  */
 public external interface ChildNode : JsAny {
-    fun before(vararg nodes: JsAny?)
-    fun after(vararg nodes: JsAny?)
-    fun replaceWith(vararg nodes: JsAny?)
+    fun before(vararg nodes: Node)
+    fun before(vararg nodes: String)
+    fun after(vararg nodes: Node)
+    fun after(vararg nodes: String)
+    fun replaceWith(vararg nodes: Node)
+    fun replaceWith(vararg nodes: String)
     fun remove()
 }
 
@@ -4695,7 +4708,7 @@ public external open class Document : Node, GlobalEventHandlers, DocumentAndElem
     override var ondurationchange: ((Event) -> Unit)?
     override var onemptied: ((Event) -> Unit)?
     override var onended: ((Event) -> Unit)?
-    override var onerror: ((JsAny?, String, Int, Int, JsAny?) -> JsAny?)?
+    override var onerror: ((JsAny? /* Event|String */, String, Int, Int, JsAny?) -> JsAny?)?
     override var onfocus: ((FocusEvent) -> Unit)?
     override var oninput: ((InputEvent) -> Unit)?
     override var oninvalid: ((Event) -> Unit)?
@@ -4795,14 +4808,22 @@ public external open class Document : Node, GlobalEventHandlers, DocumentAndElem
     fun createTouchList(vararg touches: Touch): TouchList
     fun exitFullscreen(): Promise<Nothing?>
     override fun getElementById(elementId: String): Element?
-    override fun prepend(vararg nodes: JsAny?)
-    override fun append(vararg nodes: JsAny?)
+    override fun prepend(vararg nodes: Node)
+    override fun prepend(vararg nodes: String)
+    override fun append(vararg nodes: Node)
+    override fun append(vararg nodes: String)
     override fun querySelector(selectors: String): Element?
     override fun querySelectorAll(selectors: String): NodeList
     override fun getBoxQuads(options: BoxQuadOptions /* = definedExternally */): JsArray<DOMQuad>
-    override fun convertQuadFromNode(quad: JsAny?, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertRectFromNode(rect: DOMRectReadOnly, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertPointFromNode(point: DOMPointInit, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertQuadFromNode(quad: JsAny?, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertPointFromNode(point: DOMPointInit, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
 
     companion object {
         val ELEMENT_NODE: Short
@@ -4915,8 +4936,10 @@ public external open class DocumentFragment : Node, NonElementParentNode, Parent
     override val lastElementChild: Element?
     override val childElementCount: Int
     override fun getElementById(elementId: String): Element?
-    override fun prepend(vararg nodes: JsAny?)
-    override fun append(vararg nodes: JsAny?)
+    override fun prepend(vararg nodes: Node)
+    override fun prepend(vararg nodes: String)
+    override fun append(vararg nodes: Node)
+    override fun append(vararg nodes: String)
     override fun querySelector(selectors: String): Element?
     override fun querySelectorAll(selectors: String): NodeList
 
@@ -5023,7 +5046,8 @@ public external abstract class Element : Node, ParentNode, NonDocumentTypeChildN
     fun getClientRects(): JsArray<DOMRect>
     fun getBoundingClientRect(): DOMRect
     fun scrollIntoView()
-    fun scrollIntoView(arg: JsAny?)
+    fun scrollIntoView(arg: Boolean)
+    fun scrollIntoView(arg: JsAny)
     fun scroll(options: ScrollToOptions = definedExternally)
     fun scroll(x: Double, y: Double)
     fun scrollTo(options: ScrollToOptions = definedExternally)
@@ -5166,12 +5190,21 @@ public external open class Text(data: String = definedExternally) : CharacterDat
     override val nextElementSibling: Element?
     fun splitText(offset: Int): Text
     override fun getBoxQuads(options: BoxQuadOptions /* = definedExternally */): JsArray<DOMQuad>
-    override fun convertQuadFromNode(quad: JsAny?, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertRectFromNode(rect: DOMRectReadOnly, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertPointFromNode(point: DOMPointInit, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
-    override fun before(vararg nodes: JsAny?)
-    override fun after(vararg nodes: JsAny?)
-    override fun replaceWith(vararg nodes: JsAny?)
+    override fun convertQuadFromNode(quad: JsAny?, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertPointFromNode(point: DOMPointInit, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun before(vararg nodes: Node)
+    override fun before(vararg nodes: String)
+    override fun after(vararg nodes: Node)
+    override fun after(vararg nodes: String)
+    override fun replaceWith(vararg nodes: Node)
+    override fun replaceWith(vararg nodes: String)
     override fun remove()
 
     companion object {
@@ -5256,9 +5289,12 @@ public external abstract class ProcessingInstruction : CharacterData, LinkStyle,
 public external open class Comment(data: String = definedExternally) : CharacterData, JsAny {
     override val previousElementSibling: Element?
     override val nextElementSibling: Element?
-    override fun before(vararg nodes: JsAny?)
-    override fun after(vararg nodes: JsAny?)
-    override fun replaceWith(vararg nodes: JsAny?)
+    override fun before(vararg nodes: Node)
+    override fun before(vararg nodes: String)
+    override fun after(vararg nodes: Node)
+    override fun after(vararg nodes: String)
+    override fun replaceWith(vararg nodes: Node)
+    override fun replaceWith(vararg nodes: String)
     override fun remove()
 
     companion object {
@@ -5703,13 +5739,13 @@ public external interface BoxQuadOptions : JsAny {
     var box: CSSBoxType? /* = CSSBoxType.BORDER */
         get() = definedExternally
         set(value) = definedExternally
-    var relativeTo: JsAny?
+    var relativeTo: JsAny? /* Text|Element|CSSPseudoElement|Document */
         get() = definedExternally
         set(value) = definedExternally
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun BoxQuadOptions(box: CSSBoxType? = CSSBoxType.BORDER, relativeTo: JsAny? = undefined): BoxQuadOptions { js("return { box, relativeTo };") }
+public fun BoxQuadOptions(box: CSSBoxType? = CSSBoxType.BORDER, relativeTo: JsAny? /* Text|Element|CSSPseudoElement|Document */ = undefined): BoxQuadOptions { js("return { box, relativeTo };") }
 
 public external interface ConvertCoordinateOptions : JsAny {
     var fromBox: CSSBoxType? /* = CSSBoxType.BORDER */
@@ -5728,9 +5764,15 @@ public fun ConvertCoordinateOptions(fromBox: CSSBoxType? = CSSBoxType.BORDER, to
  */
 public external interface GeometryUtils : JsAny {
     fun getBoxQuads(options: BoxQuadOptions = definedExternally): JsArray<DOMQuad>
-    fun convertQuadFromNode(quad: JsAny?, from: JsAny?, options: ConvertCoordinateOptions = definedExternally): DOMQuad
-    fun convertRectFromNode(rect: DOMRectReadOnly, from: JsAny?, options: ConvertCoordinateOptions = definedExternally): DOMQuad
-    fun convertPointFromNode(point: DOMPointInit, from: JsAny?, options: ConvertCoordinateOptions = definedExternally): DOMPoint
+    fun convertQuadFromNode(quad: JsAny?, from: Text, options: ConvertCoordinateOptions = definedExternally): DOMQuad
+    fun convertQuadFromNode(quad: JsAny?, from: Element, options: ConvertCoordinateOptions = definedExternally): DOMQuad
+    fun convertQuadFromNode(quad: JsAny?, from: Document, options: ConvertCoordinateOptions = definedExternally): DOMQuad
+    fun convertRectFromNode(rect: DOMRectReadOnly, from: Text, options: ConvertCoordinateOptions = definedExternally): DOMQuad
+    fun convertRectFromNode(rect: DOMRectReadOnly, from: Element, options: ConvertCoordinateOptions = definedExternally): DOMQuad
+    fun convertRectFromNode(rect: DOMRectReadOnly, from: Document, options: ConvertCoordinateOptions = definedExternally): DOMQuad
+    fun convertPointFromNode(point: DOMPointInit, from: Text, options: ConvertCoordinateOptions = definedExternally): DOMPoint
+    fun convertPointFromNode(point: DOMPointInit, from: Element, options: ConvertCoordinateOptions = definedExternally): DOMPoint
+    fun convertPointFromNode(point: DOMPointInit, from: Document, options: ConvertCoordinateOptions = definedExternally): DOMPoint
 }
 
 /**
@@ -5800,7 +5842,7 @@ public external open class Image(width: Int = definedExternally, height: Int = d
     override var ondurationchange: ((Event) -> Unit)?
     override var onemptied: ((Event) -> Unit)?
     override var onended: ((Event) -> Unit)?
-    override var onerror: ((JsAny?, String, Int, Int, JsAny?) -> JsAny?)?
+    override var onerror: ((JsAny? /* Event|String */, String, Int, Int, JsAny?) -> JsAny?)?
     override var onfocus: ((FocusEvent) -> Unit)?
     override var oninput: ((InputEvent) -> Unit)?
     override var oninvalid: ((Event) -> Unit)?
@@ -5862,18 +5904,29 @@ public external open class Image(width: Int = definedExternally, height: Int = d
     override val previousElementSibling: Element?
     override val nextElementSibling: Element?
     override val assignedSlot: HTMLSlotElement?
-    override fun prepend(vararg nodes: JsAny?)
-    override fun append(vararg nodes: JsAny?)
+    override fun prepend(vararg nodes: Node)
+    override fun prepend(vararg nodes: String)
+    override fun append(vararg nodes: Node)
+    override fun append(vararg nodes: String)
     override fun querySelector(selectors: String): Element?
     override fun querySelectorAll(selectors: String): NodeList
-    override fun before(vararg nodes: JsAny?)
-    override fun after(vararg nodes: JsAny?)
-    override fun replaceWith(vararg nodes: JsAny?)
+    override fun before(vararg nodes: Node)
+    override fun before(vararg nodes: String)
+    override fun after(vararg nodes: Node)
+    override fun after(vararg nodes: String)
+    override fun replaceWith(vararg nodes: Node)
+    override fun replaceWith(vararg nodes: String)
     override fun remove()
     override fun getBoxQuads(options: BoxQuadOptions /* = definedExternally */): JsArray<DOMQuad>
-    override fun convertQuadFromNode(quad: JsAny?, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertRectFromNode(rect: DOMRectReadOnly, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertPointFromNode(point: DOMPointInit, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertQuadFromNode(quad: JsAny?, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertPointFromNode(point: DOMPointInit, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
 
     companion object {
         val ELEMENT_NODE: Short
@@ -5920,7 +5973,7 @@ public external open class Audio(src: String = definedExternally) : HTMLAudioEle
     override var ondurationchange: ((Event) -> Unit)?
     override var onemptied: ((Event) -> Unit)?
     override var onended: ((Event) -> Unit)?
-    override var onerror: ((JsAny?, String, Int, Int, JsAny?) -> JsAny?)?
+    override var onerror: ((JsAny? /* Event|String */, String, Int, Int, JsAny?) -> JsAny?)?
     override var onfocus: ((FocusEvent) -> Unit)?
     override var oninput: ((InputEvent) -> Unit)?
     override var oninvalid: ((Event) -> Unit)?
@@ -5982,18 +6035,29 @@ public external open class Audio(src: String = definedExternally) : HTMLAudioEle
     override val previousElementSibling: Element?
     override val nextElementSibling: Element?
     override val assignedSlot: HTMLSlotElement?
-    override fun prepend(vararg nodes: JsAny?)
-    override fun append(vararg nodes: JsAny?)
+    override fun prepend(vararg nodes: Node)
+    override fun prepend(vararg nodes: String)
+    override fun append(vararg nodes: Node)
+    override fun append(vararg nodes: String)
     override fun querySelector(selectors: String): Element?
     override fun querySelectorAll(selectors: String): NodeList
-    override fun before(vararg nodes: JsAny?)
-    override fun after(vararg nodes: JsAny?)
-    override fun replaceWith(vararg nodes: JsAny?)
+    override fun before(vararg nodes: Node)
+    override fun before(vararg nodes: String)
+    override fun after(vararg nodes: Node)
+    override fun after(vararg nodes: String)
+    override fun replaceWith(vararg nodes: Node)
+    override fun replaceWith(vararg nodes: String)
     override fun remove()
     override fun getBoxQuads(options: BoxQuadOptions /* = definedExternally */): JsArray<DOMQuad>
-    override fun convertQuadFromNode(quad: JsAny?, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertRectFromNode(rect: DOMRectReadOnly, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertPointFromNode(point: DOMPointInit, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertQuadFromNode(quad: JsAny?, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertPointFromNode(point: DOMPointInit, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
 
     companion object {
         val NETWORK_EMPTY: Short
@@ -6052,7 +6116,7 @@ public external open class Option(text: String = definedExternally, value: Strin
     override var ondurationchange: ((Event) -> Unit)?
     override var onemptied: ((Event) -> Unit)?
     override var onended: ((Event) -> Unit)?
-    override var onerror: ((JsAny?, String, Int, Int, JsAny?) -> JsAny?)?
+    override var onerror: ((JsAny? /* Event|String */, String, Int, Int, JsAny?) -> JsAny?)?
     override var onfocus: ((FocusEvent) -> Unit)?
     override var oninput: ((InputEvent) -> Unit)?
     override var oninvalid: ((Event) -> Unit)?
@@ -6114,18 +6178,29 @@ public external open class Option(text: String = definedExternally, value: Strin
     override val previousElementSibling: Element?
     override val nextElementSibling: Element?
     override val assignedSlot: HTMLSlotElement?
-    override fun prepend(vararg nodes: JsAny?)
-    override fun append(vararg nodes: JsAny?)
+    override fun prepend(vararg nodes: Node)
+    override fun prepend(vararg nodes: String)
+    override fun append(vararg nodes: Node)
+    override fun append(vararg nodes: String)
     override fun querySelector(selectors: String): Element?
     override fun querySelectorAll(selectors: String): NodeList
-    override fun before(vararg nodes: JsAny?)
-    override fun after(vararg nodes: JsAny?)
-    override fun replaceWith(vararg nodes: JsAny?)
+    override fun before(vararg nodes: Node)
+    override fun before(vararg nodes: String)
+    override fun after(vararg nodes: Node)
+    override fun after(vararg nodes: String)
+    override fun replaceWith(vararg nodes: Node)
+    override fun replaceWith(vararg nodes: String)
     override fun remove()
     override fun getBoxQuads(options: BoxQuadOptions /* = definedExternally */): JsArray<DOMQuad>
-    override fun convertQuadFromNode(quad: JsAny?, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertRectFromNode(rect: DOMRectReadOnly, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
-    override fun convertPointFromNode(point: DOMPointInit, from: JsAny?, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertQuadFromNode(quad: JsAny?, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertQuadFromNode(quad: JsAny?, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertRectFromNode(rect: DOMRectReadOnly, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMQuad
+    override fun convertPointFromNode(point: DOMPointInit, from: Text, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Element, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
+    override fun convertPointFromNode(point: DOMPointInit, from: Document, options: ConvertCoordinateOptions /* = definedExternally */): DOMPoint
 
     companion object {
         val ELEMENT_NODE: Short
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.mediacapture.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.mediacapture.kt
index 9880a9a6265..815bbef1dcc 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.mediacapture.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.mediacapture.kt
@@ -175,61 +175,61 @@ public external interface MediaTrackConstraints : MediaTrackConstraintSet, JsAny
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun MediaTrackConstraints(advanced: JsArray<MediaTrackConstraintSet>? = undefined, width: JsAny? = undefined, height: JsAny? = undefined, aspectRatio: JsAny? = undefined, frameRate: JsAny? = undefined, facingMode: JsAny? = undefined, resizeMode: JsAny? = undefined, volume: JsAny? = undefined, sampleRate: JsAny? = undefined, sampleSize: JsAny? = undefined, echoCancellation: JsAny? = undefined, autoGainControl: JsAny? = undefined, noiseSuppression: JsAny? = undefined, latency: JsAny? = undefined, channelCount: JsAny? = undefined, deviceId: JsAny? = undefined, groupId: JsAny? = undefined): MediaTrackConstraints { js("return { advanced, width, height, aspectRatio, frameRate, facingMode, resizeMode, volume, sampleRate, sampleSize, echoCancellation, autoGainControl, noiseSuppression, latency, channelCount, deviceId, groupId };") }
+public fun MediaTrackConstraints(advanced: JsArray<MediaTrackConstraintSet>? = undefined, width: JsAny? /* Int|ConstrainULongRange */ = undefined, height: JsAny? /* Int|ConstrainULongRange */ = undefined, aspectRatio: JsAny? /* Double|ConstrainDoubleRange */ = undefined, frameRate: JsAny? /* Double|ConstrainDoubleRange */ = undefined, facingMode: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined, resizeMode: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined, volume: JsAny? /* Double|ConstrainDoubleRange */ = undefined, sampleRate: JsAny? /* Int|ConstrainULongRange */ = undefined, sampleSize: JsAny? /* Int|ConstrainULongRange */ = undefined, echoCancellation: JsAny? /* Boolean|ConstrainBooleanParameters */ = undefined, autoGainControl: JsAny? /* Boolean|ConstrainBooleanParameters */ = undefined, noiseSuppression: JsAny? /* Boolean|ConstrainBooleanParameters */ = undefined, latency: JsAny? /* Double|ConstrainDoubleRange */ = undefined, channelCount: JsAny? /* Int|ConstrainULongRange */ = undefined, deviceId: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined, groupId: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined): MediaTrackConstraints { js("return { advanced, width, height, aspectRatio, frameRate, facingMode, resizeMode, volume, sampleRate, sampleSize, echoCancellation, autoGainControl, noiseSuppression, latency, channelCount, deviceId, groupId };") }
 
 public external interface MediaTrackConstraintSet : JsAny {
-    var width: JsAny?
+    var width: JsAny? /* Int|ConstrainULongRange */
         get() = definedExternally
         set(value) = definedExternally
-    var height: JsAny?
+    var height: JsAny? /* Int|ConstrainULongRange */
         get() = definedExternally
         set(value) = definedExternally
-    var aspectRatio: JsAny?
+    var aspectRatio: JsAny? /* Double|ConstrainDoubleRange */
         get() = definedExternally
         set(value) = definedExternally
-    var frameRate: JsAny?
+    var frameRate: JsAny? /* Double|ConstrainDoubleRange */
         get() = definedExternally
         set(value) = definedExternally
-    var facingMode: JsAny?
+    var facingMode: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */
         get() = definedExternally
         set(value) = definedExternally
-    var resizeMode: JsAny?
+    var resizeMode: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */
         get() = definedExternally
         set(value) = definedExternally
-    var volume: JsAny?
+    var volume: JsAny? /* Double|ConstrainDoubleRange */
         get() = definedExternally
         set(value) = definedExternally
-    var sampleRate: JsAny?
+    var sampleRate: JsAny? /* Int|ConstrainULongRange */
         get() = definedExternally
         set(value) = definedExternally
-    var sampleSize: JsAny?
+    var sampleSize: JsAny? /* Int|ConstrainULongRange */
         get() = definedExternally
         set(value) = definedExternally
-    var echoCancellation: JsAny?
+    var echoCancellation: JsAny? /* Boolean|ConstrainBooleanParameters */
         get() = definedExternally
         set(value) = definedExternally
-    var autoGainControl: JsAny?
+    var autoGainControl: JsAny? /* Boolean|ConstrainBooleanParameters */
         get() = definedExternally
         set(value) = definedExternally
-    var noiseSuppression: JsAny?
+    var noiseSuppression: JsAny? /* Boolean|ConstrainBooleanParameters */
         get() = definedExternally
         set(value) = definedExternally
-    var latency: JsAny?
+    var latency: JsAny? /* Double|ConstrainDoubleRange */
         get() = definedExternally
         set(value) = definedExternally
-    var channelCount: JsAny?
+    var channelCount: JsAny? /* Int|ConstrainULongRange */
         get() = definedExternally
         set(value) = definedExternally
-    var deviceId: JsAny?
+    var deviceId: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */
         get() = definedExternally
         set(value) = definedExternally
-    var groupId: JsAny?
+    var groupId: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */
         get() = definedExternally
         set(value) = definedExternally
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun MediaTrackConstraintSet(width: JsAny? = undefined, height: JsAny? = undefined, aspectRatio: JsAny? = undefined, frameRate: JsAny? = undefined, facingMode: JsAny? = undefined, resizeMode: JsAny? = undefined, volume: JsAny? = undefined, sampleRate: JsAny? = undefined, sampleSize: JsAny? = undefined, echoCancellation: JsAny? = undefined, autoGainControl: JsAny? = undefined, noiseSuppression: JsAny? = undefined, latency: JsAny? = undefined, channelCount: JsAny? = undefined, deviceId: JsAny? = undefined, groupId: JsAny? = undefined): MediaTrackConstraintSet { js("return { width, height, aspectRatio, frameRate, facingMode, resizeMode, volume, sampleRate, sampleSize, echoCancellation, autoGainControl, noiseSuppression, latency, channelCount, deviceId, groupId };") }
+public fun MediaTrackConstraintSet(width: JsAny? /* Int|ConstrainULongRange */ = undefined, height: JsAny? /* Int|ConstrainULongRange */ = undefined, aspectRatio: JsAny? /* Double|ConstrainDoubleRange */ = undefined, frameRate: JsAny? /* Double|ConstrainDoubleRange */ = undefined, facingMode: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined, resizeMode: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined, volume: JsAny? /* Double|ConstrainDoubleRange */ = undefined, sampleRate: JsAny? /* Int|ConstrainULongRange */ = undefined, sampleSize: JsAny? /* Int|ConstrainULongRange */ = undefined, echoCancellation: JsAny? /* Boolean|ConstrainBooleanParameters */ = undefined, autoGainControl: JsAny? /* Boolean|ConstrainBooleanParameters */ = undefined, noiseSuppression: JsAny? /* Boolean|ConstrainBooleanParameters */ = undefined, latency: JsAny? /* Double|ConstrainDoubleRange */ = undefined, channelCount: JsAny? /* Int|ConstrainULongRange */ = undefined, deviceId: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined, groupId: JsAny? /* String|JsArray<JsString>|ConstrainDOMStringParameters */ = undefined): MediaTrackConstraintSet { js("return { width, height, aspectRatio, frameRate, facingMode, resizeMode, volume, sampleRate, sampleSize, echoCancellation, autoGainControl, noiseSuppression, latency, channelCount, deviceId, groupId };") }
 
 /**
  * Exposes the JavaScript [MediaTrackSettings](https://developer.mozilla.org/en/docs/Web/API/MediaTrackSettings) to Kotlin
@@ -358,16 +358,16 @@ public external abstract class InputDeviceInfo : MediaDeviceInfo, JsAny {
  * Exposes the JavaScript [MediaStreamConstraints](https://developer.mozilla.org/en/docs/Web/API/MediaStreamConstraints) to Kotlin
  */
 public external interface MediaStreamConstraints : JsAny {
-    var video: JsAny? /* = false */
+    var video: JsAny? /* Boolean|MediaTrackConstraints */
         get() = definedExternally
         set(value) = definedExternally
-    var audio: JsAny? /* = false */
+    var audio: JsAny? /* Boolean|MediaTrackConstraints */
         get() = definedExternally
         set(value) = definedExternally
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun MediaStreamConstraints(video: JsAny? = false.toJsBoolean(), audio: JsAny? = false.toJsBoolean()): MediaStreamConstraints { js("return { video, audio };") }
+public fun MediaStreamConstraints(video: JsAny? /* Boolean|MediaTrackConstraints */ = false.toJsBoolean(), audio: JsAny? /* Boolean|MediaTrackConstraints */ = false.toJsBoolean()): MediaStreamConstraints { js("return { video, audio };") }
 
 public external interface ConstrainablePattern : JsAny {
     var onoverconstrained: ((Event) -> Unit)?
@@ -449,16 +449,16 @@ public fun ConstrainBooleanParameters(exact: Boolean? = undefined, ideal: Boolea
  * Exposes the JavaScript [ConstrainDOMStringParameters](https://developer.mozilla.org/en/docs/Web/API/ConstrainDOMStringParameters) to Kotlin
  */
 public external interface ConstrainDOMStringParameters : JsAny {
-    var exact: JsAny?
+    var exact: JsAny? /* String|JsArray<JsString> */
         get() = definedExternally
         set(value) = definedExternally
-    var ideal: JsAny?
+    var ideal: JsAny? /* String|JsArray<JsString> */
         get() = definedExternally
         set(value) = definedExternally
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun ConstrainDOMStringParameters(exact: JsAny? = undefined, ideal: JsAny? = undefined): ConstrainDOMStringParameters { js("return { exact, ideal };") }
+public fun ConstrainDOMStringParameters(exact: JsAny? /* String|JsArray<JsString> */ = undefined, ideal: JsAny? /* String|JsArray<JsString> */ = undefined): ConstrainDOMStringParameters { js("return { exact, ideal };") }
 
 public external interface Capabilities : JsAny
 
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.url.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.url.kt
index e5ee9c14dd3..8c57b3e8891 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.url.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.dom.url.kt
@@ -43,7 +43,7 @@ public external open class URL(url: String, base: String = definedExternally) :
 /**
  * Exposes the JavaScript [URLSearchParams](https://developer.mozilla.org/en/docs/Web/API/URLSearchParams) to Kotlin
  */
-public external open class URLSearchParams(init: JsAny? = definedExternally) : JsAny {
+public external open class URLSearchParams(init: JsAny? /* String|URLSearchParams */ = definedExternally) : JsAny {
     fun append(name: String, value: String)
     fun delete(name: String)
     fun get(name: String): String?
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.fetch.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.fetch.kt
index fb7970d8b2a..e8a4dc9a4ce 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.fetch.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.fetch.kt
@@ -16,7 +16,7 @@ import org.w3c.xhr.*
 /**
  * Exposes the JavaScript [Headers](https://developer.mozilla.org/en/docs/Web/API/Headers) to Kotlin
  */
-public external open class Headers(init: JsAny? = definedExternally) : JsAny {
+public external open class Headers(init: JsAny? /* Headers|JsArray<JsArray<JsString>>|OpenEndedDictionary<JsString> */ = definedExternally) : JsAny {
     fun append(name: String, value: String)
     fun delete(name: String)
     fun get(name: String): String?
@@ -39,7 +39,7 @@ public external interface Body : JsAny {
 /**
  * Exposes the JavaScript [Request](https://developer.mozilla.org/en/docs/Web/API/Request) to Kotlin
  */
-public external open class Request(input: JsAny?, init: RequestInit = definedExternally) : Body, JsAny {
+public external open class Request(input: JsAny? /* Request|String */, init: RequestInit = definedExternally) : Body, JsAny {
     open val method: String
     open val url: String
     open val headers: Headers
@@ -66,10 +66,10 @@ public external interface RequestInit : JsAny {
     var method: String?
         get() = definedExternally
         set(value) = definedExternally
-    var headers: JsAny?
+    var headers: JsAny? /* Headers|JsArray<JsArray<JsString>>|OpenEndedDictionary<JsString> */
         get() = definedExternally
         set(value) = definedExternally
-    var body: JsAny?
+    var body: JsAny? /* Blob|BufferSource|FormData|URLSearchParams|String */
         get() = definedExternally
         set(value) = definedExternally
     var referrer: String?
@@ -102,12 +102,12 @@ public external interface RequestInit : JsAny {
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun RequestInit(method: String? = undefined, headers: JsAny? = undefined, body: JsAny? = undefined, referrer: String? = undefined, referrerPolicy: JsAny? = undefined, mode: RequestMode? = undefined, credentials: RequestCredentials? = undefined, cache: RequestCache? = undefined, redirect: RequestRedirect? = undefined, integrity: String? = undefined, keepalive: Boolean? = undefined, window: JsAny? = undefined): RequestInit { js("return { method, headers, body, referrer, referrerPolicy, mode, credentials, cache, redirect, integrity, keepalive, window };") }
+public fun RequestInit(method: String? = undefined, headers: JsAny? /* Headers|JsArray<JsArray<JsString>>|OpenEndedDictionary<JsString> */ = undefined, body: JsAny? /* Blob|BufferSource|FormData|URLSearchParams|String */ = undefined, referrer: String? = undefined, referrerPolicy: JsAny? = undefined, mode: RequestMode? = undefined, credentials: RequestCredentials? = undefined, cache: RequestCache? = undefined, redirect: RequestRedirect? = undefined, integrity: String? = undefined, keepalive: Boolean? = undefined, window: JsAny? = undefined): RequestInit { js("return { method, headers, body, referrer, referrerPolicy, mode, credentials, cache, redirect, integrity, keepalive, window };") }
 
 /**
  * Exposes the JavaScript [Response](https://developer.mozilla.org/en/docs/Web/API/Response) to Kotlin
  */
-public external open class Response(body: JsAny? = definedExternally, init: ResponseInit = definedExternally) : Body, JsAny {
+public external open class Response(body: JsAny? /* JsAny?|ReadableStream */ = definedExternally, init: ResponseInit = definedExternally) : Body, JsAny {
     open val type: ResponseType
     open val url: String
     open val redirected: Boolean
@@ -138,13 +138,13 @@ public external interface ResponseInit : JsAny {
     var statusText: String? /* = "OK" */
         get() = definedExternally
         set(value) = definedExternally
-    var headers: JsAny?
+    var headers: JsAny? /* Headers|JsArray<JsArray<JsString>>|OpenEndedDictionary<JsString> */
         get() = definedExternally
         set(value) = definedExternally
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun ResponseInit(status: Short? = 200, statusText: String? = "OK", headers: JsAny? = undefined): ResponseInit { js("return { status, statusText, headers };") }
+public fun ResponseInit(status: Short? = 200, statusText: String? = "OK", headers: JsAny? /* Headers|JsArray<JsArray<JsString>>|OpenEndedDictionary<JsString> */ = undefined): ResponseInit { js("return { status, statusText, headers };") }
 
 /* please, don't implement this interface! */
 @JsName("null")
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.files.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.files.kt
index 4a9504d3018..94a1db875d9 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.files.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.files.kt
@@ -17,7 +17,7 @@ import org.w3c.xhr.*
 /**
  * Exposes the JavaScript [Blob](https://developer.mozilla.org/en/docs/Web/API/Blob) to Kotlin
  */
-public external open class Blob(blobParts: JsArray<JsAny?> = definedExternally, options: BlobPropertyBag = definedExternally) : MediaProvider, ImageBitmapSource, JsAny {
+public external open class Blob(blobParts: JsArray<JsAny? /* BufferSource|Blob|String */> = definedExternally, options: BlobPropertyBag = definedExternally) : MediaProvider, ImageBitmapSource, JsAny {
     open val size: JsNumber
     open val type: String
     open val isClosed: Boolean
@@ -37,7 +37,7 @@ public fun BlobPropertyBag(type: String? = ""): BlobPropertyBag { js("return { t
 /**
  * Exposes the JavaScript [File](https://developer.mozilla.org/en/docs/Web/API/File) to Kotlin
  */
-public external open class File(fileBits: JsArray<JsAny?>, fileName: String, options: FilePropertyBag = definedExternally) : Blob, JsAny {
+public external open class File(fileBits: JsArray<JsAny? /* BufferSource|Blob|String */>, fileName: String, options: FilePropertyBag = definedExternally) : Blob, JsAny {
     open val name: String
     open val lastModified: Int
 }
@@ -68,7 +68,7 @@ public operator fun FileList.get(index: Int): File? = getMethodImplForFileList(t
  */
 public external open class FileReader : EventTarget, JsAny {
     open val readyState: Short
-    open val result: JsAny?
+    open val result: JsAny? /* String|ArrayBuffer */
     open val error: JsAny?
     var onloadstart: ((ProgressEvent) -> Unit)?
     var onprogress: ((ProgressEvent) -> Unit)?
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.notifications.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.notifications.kt
index 7b519cad06d..39e812e65eb 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.notifications.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.notifications.kt
@@ -71,7 +71,7 @@ public external interface NotificationOptions : JsAny {
     var sound: String?
         get() = definedExternally
         set(value) = definedExternally
-    var vibrate: JsAny?
+    var vibrate: JsAny? /* Int|JsArray<JsNumber> */
         get() = definedExternally
         set(value) = definedExternally
     var timestamp: JsNumber?
@@ -101,7 +101,7 @@ public external interface NotificationOptions : JsAny {
 }
 
 @Suppress("UNUSED_PARAMETER")
-public fun NotificationOptions(dir: NotificationDirection? = NotificationDirection.AUTO, lang: String? = "", body: String? = "", tag: String? = "", image: String? = undefined, icon: String? = undefined, badge: String? = undefined, sound: String? = undefined, vibrate: JsAny? = undefined, timestamp: JsNumber? = undefined, renotify: Boolean? = false, silent: Boolean? = false, noscreen: Boolean? = false, requireInteraction: Boolean? = false, sticky: Boolean? = false, data: JsAny? = null, actions: JsArray<NotificationAction>? = JsArray()): NotificationOptions { js("return { dir, lang, body, tag, image, icon, badge, sound, vibrate, timestamp, renotify, silent, noscreen, requireInteraction, sticky, data, actions };") }
+public fun NotificationOptions(dir: NotificationDirection? = NotificationDirection.AUTO, lang: String? = "", body: String? = "", tag: String? = "", image: String? = undefined, icon: String? = undefined, badge: String? = undefined, sound: String? = undefined, vibrate: JsAny? /* Int|JsArray<JsNumber> */ = undefined, timestamp: JsNumber? = undefined, renotify: Boolean? = false, silent: Boolean? = false, noscreen: Boolean? = false, requireInteraction: Boolean? = false, sticky: Boolean? = false, data: JsAny? = null, actions: JsArray<NotificationAction>? = JsArray()): NotificationOptions { js("return { dir, lang, body, tag, image, icon, badge, sound, vibrate, timestamp, renotify, silent, noscreen, requireInteraction, sticky, data, actions };") }
 
 public external interface NotificationAction : JsAny {
     var action: String?
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.workers.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.workers.kt
index a95cdb07c1f..a2965cadc2b 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.workers.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.workers.kt
@@ -316,13 +316,21 @@ public fun ExtendableMessageEventInit(data: JsAny? = undefined, origin: String?
  * Exposes the JavaScript [Cache](https://developer.mozilla.org/en/docs/Web/API/Cache) to Kotlin
  */
 public external abstract class Cache : JsAny {
-    fun match(request: JsAny?, options: CacheQueryOptions = definedExternally): Promise<JsAny?>
-    fun matchAll(request: JsAny? = definedExternally, options: CacheQueryOptions = definedExternally): Promise<JsArray<Response>>
-    fun add(request: JsAny?): Promise<Nothing?>
-    fun addAll(requests: JsArray<JsAny?>): Promise<Nothing?>
-    fun put(request: JsAny?, response: Response): Promise<Nothing?>
-    fun delete(request: JsAny?, options: CacheQueryOptions = definedExternally): Promise<JsBoolean>
-    fun keys(request: JsAny? = definedExternally, options: CacheQueryOptions = definedExternally): Promise<JsArray<Request>>
+    fun match(request: Request, options: CacheQueryOptions = definedExternally): Promise<JsAny?>
+    fun match(request: String, options: CacheQueryOptions = definedExternally): Promise<JsAny?>
+    fun matchAll(request: Request, options: CacheQueryOptions = definedExternally): Promise<JsArray<Response>>
+    fun matchAll(request: String, options: CacheQueryOptions = definedExternally): Promise<JsArray<Response>>
+    fun matchAll(): Promise<JsArray<Response>>
+    fun add(request: Request): Promise<Nothing?>
+    fun add(request: String): Promise<Nothing?>
+    fun addAll(requests: JsArray<JsAny? /* Request|String */>): Promise<Nothing?>
+    fun put(request: Request, response: Response): Promise<Nothing?>
+    fun put(request: String, response: Response): Promise<Nothing?>
+    fun delete(request: Request, options: CacheQueryOptions = definedExternally): Promise<JsBoolean>
+    fun delete(request: String, options: CacheQueryOptions = definedExternally): Promise<JsBoolean>
+    fun keys(request: Request, options: CacheQueryOptions = definedExternally): Promise<JsArray<Request>>
+    fun keys(request: String, options: CacheQueryOptions = definedExternally): Promise<JsArray<Request>>
+    fun keys(): Promise<JsArray<Request>>
 }
 
 public external interface CacheQueryOptions : JsAny {
@@ -365,7 +373,8 @@ public fun CacheBatchOperation(type: String? = undefined, request: Request? = un
  * Exposes the JavaScript [CacheStorage](https://developer.mozilla.org/en/docs/Web/API/CacheStorage) to Kotlin
  */
 public external abstract class CacheStorage : JsAny {
-    fun match(request: JsAny?, options: CacheQueryOptions = definedExternally): Promise<JsAny?>
+    fun match(request: Request, options: CacheQueryOptions = definedExternally): Promise<JsAny?>
+    fun match(request: String, options: CacheQueryOptions = definedExternally): Promise<JsAny?>
     fun has(cacheName: String): Promise<JsBoolean>
     fun open(cacheName: String): Promise<Cache>
     fun delete(cacheName: String): Promise<JsBoolean>
diff --git a/libraries/stdlib/wasm/src/org.w3c/org.w3c.xhr.kt b/libraries/stdlib/wasm/src/org.w3c/org.w3c.xhr.kt
index bce47f36701..c3f09448038 100644
--- a/libraries/stdlib/wasm/src/org.w3c/org.w3c.xhr.kt
+++ b/libraries/stdlib/wasm/src/org.w3c/org.w3c.xhr.kt
@@ -12,6 +12,7 @@ import kotlin.js.*
 import org.khronos.webgl.*
 import org.w3c.dom.*
 import org.w3c.dom.events.*
+import org.w3c.dom.url.*
 import org.w3c.files.*
 
 /**
@@ -48,7 +49,12 @@ public external open class XMLHttpRequest : XMLHttpRequestEventTarget, JsAny {
     fun open(method: String, url: String)
     fun open(method: String, url: String, async: Boolean, username: String? = definedExternally, password: String? = definedExternally)
     fun setRequestHeader(name: String, value: String)
-    fun send(body: JsAny? = definedExternally)
+    fun send(body: Document)
+    fun send(body: Blob)
+    fun send(body: FormData)
+    fun send(body: URLSearchParams)
+    fun send(body: String)
+    fun send()
     fun abort()
     fun getResponseHeader(name: String): String?
     fun getAllResponseHeaders(): String
@@ -70,8 +76,8 @@ public external open class FormData(form: HTMLFormElement = definedExternally) :
     fun append(name: String, value: String)
     fun append(name: String, value: Blob, filename: String = definedExternally)
     fun delete(name: String)
-    fun get(name: String): JsAny?
-    fun getAll(name: String): JsArray<JsAny?>
+    fun get(name: String): JsAny? /* File|String */
+    fun getAll(name: String): JsArray<JsAny? /* File|String */>
     fun has(name: String): Boolean
     fun set(name: String, value: String)
     fun set(name: String, value: Blob, filename: String = definedExternally)
diff --git a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/addOverloadsForUnions.kt b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/addOverloadsForUnions.kt
new file mode 100644
index 00000000000..25fff150e4c
--- /dev/null
+++ b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/addOverloadsForUnions.kt
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.tools.dukat.wasm
+
+import org.jetbrains.dukat.idlDeclarations.*
+import org.jetbrains.dukat.idlLowerings.IDLLowering
+
+class UnionParametersOverloadsLowering : IDLLowering {
+    // Types that are present as union components, but somehow missing IDL declarations. Should be ignored.
+    private val typesMissingFromIDL: Set<String> =
+        setOf("CSSPseudoElement", "BufferSource")
+
+    override fun lowerInterfaceDeclaration(declaration: IDLInterfaceDeclaration, owner: IDLFileDeclaration): IDLInterfaceDeclaration {
+        return declaration.copy(
+            operations = declaration.operations.flatMap(::generateOverloads)
+        )
+    }
+
+    private fun generateOverloads(op: IDLOperationDeclaration): List<IDLOperationDeclaration> {
+        val numUnionTypes = op.arguments.count { it.type is IDLUnionTypeDeclaration }
+        if (numUnionTypes == 0)
+            return listOf(op)
+
+        if (numUnionTypes > 1)
+            TODO(
+                """
+                Not supported in current implementation to keep it simple.
+                If updated IDL contains multiple union arguments and this check fails,
+                consider updating the algorithm or return listOf(op) as a fallback.
+                """
+            )
+
+        val unionTypedArgumentIndex = op.arguments.indexOfFirst { it.type is IDLUnionTypeDeclaration }
+        val unionTypedArgument = op.arguments[unionTypedArgumentIndex]
+        val unionType = unionTypedArgument.type as IDLUnionTypeDeclaration
+
+        var unionMembersFlattened = unionType.unionMembers
+        while (unionMembersFlattened.any { it is IDLUnionTypeDeclaration }) {
+            unionMembersFlattened = unionMembersFlattened.flatMap {
+                if (it is IDLUnionTypeDeclaration) it.unionMembers else listOf(it)
+            }
+        }
+
+        val result = unionMembersFlattened.mapNotNull { unionMember ->
+            if (unionMember.name in typesMissingFromIDL)
+                return@mapNotNull null
+
+            op.copy(
+                arguments = op.arguments.mapIndexed { argumentIndex, argument: IDLArgumentDeclaration ->
+                    if (argumentIndex == unionTypedArgumentIndex) {
+                        argument.copy(type = unionMember, defaultValue = null, optional = false)
+                    } else {
+                        argument.copy()
+                    }
+                }
+            )
+        }
+
+        // If union typed argument is optional - create an overload without union argument.
+        if (unionTypedArgument.optional || unionTypedArgument.defaultValue != null) {
+            return result + op.copy(arguments = op.arguments.subList(0, unionTypedArgumentIndex))
+        }
+
+        return result
+    }
+}
+
+fun IDLSourceSetDeclaration.addOverloadsForUnions(): IDLSourceSetDeclaration {
+    return UnionParametersOverloadsLowering().lowerSourceSetDeclaration(this)
+}
\ No newline at end of file
diff --git a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/convertToModel.kt b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/convertToModel.kt
index 489a3b4b19c..9ecc3bfa587 100644
--- a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/convertToModel.kt
+++ b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/convertToModel.kt
@@ -50,6 +50,7 @@ import org.jetbrains.dukat.panic.raiseConcern
 import org.jetbrains.dukat.stdlib.TSLIBROOT
 import org.jetbrains.dukat.stdlib.isTsStdlibPrefixed
 import org.jetbrains.dukat.translator.ROOT_PACKAGENAME
+import org.jetbrains.dukat.translatorString.translate
 import java.io.File
 
 private val jsAnyHeritageModel: HeritageModel = HeritageModel(
@@ -224,6 +225,13 @@ private class IdlFileConverter(
         return when (this) {
             is IDLSingleTypeDeclaration -> convertToModel(isTypeParameter)
             is IDLFunctionTypeDeclaration -> convertToModel()
+            is IDLUnionTypeDeclaration -> TypeValueModel(
+                IdentifierEntity("JsAny"),
+                listOf(),
+                metaDescription = this.unionMembers.joinToString("|") { it.convertToModel(false).translate() },
+                null,
+                nullable = true,
+            )
             //there shouldn't be any UnionTypeDeclarations at this stage
             else -> raiseConcern("unprocessed type declaration: ${this}") {
                 TypeValueModel(
diff --git a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/resolveTypes.kt b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/resolveTypes.kt
index 39cd9c40600..653eb21830f 100644
--- a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/resolveTypes.kt
+++ b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/resolveTypes.kt
@@ -98,12 +98,8 @@ private class TypeResolver : IDLLowering {
                         nullable = declaration.nullable,
                         comment = declaration.comment
                 )
-                in failedToResolveUnionTypes -> IDLSingleTypeDeclaration(
-                    name = "\$dynamic",
-                    typeParameter = null,
-                    nullable = false,
-                    comment = declaration.comment
-                )
+                // Keeping unresolved union types as-is to process later
+                in failedToResolveUnionTypes -> declaration
                 else -> raiseConcern("unprocessed UnionTypeDeclaration: $this") { declaration }
             }
         }
@@ -203,7 +199,7 @@ private class DependencyResolver(val typeResolver: TypeResolver) : IDLLowering {
     }
 }
 
-fun IDLSourceSetDeclaration.resolveTypes(): IDLSourceSetDeclaration {
+fun IDLSourceSetDeclaration.resolveTypesKeepingUnions(): IDLSourceSetDeclaration {
     val typeResolver = TypeResolver()
     val dependencyResolver = DependencyResolver(typeResolver)
     val declarationAdder = DeclarationAdder(typeResolver)
diff --git a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/translator.kt b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/translator.kt
index 62c6034c7cd..18364eb390c 100644
--- a/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/translator.kt
+++ b/libraries/tools/dukat/src/main/kotlin/org/jetbrains/kotlin/tools/dukat/wasm/translator.kt
@@ -27,7 +27,8 @@ fun translateIdlToSourceSet(fileName: String): SourceSetModel {
         .resolveImplementsStatements()
         .resolveMixins()
         .addItemArrayLike()
-        .resolveTypes()
+        .resolveTypesKeepingUnions()
+        .addOverloadsForUnions()
         .markAbstractOrOpen()
         .addMissingMembers()
         .addOverloadsForCallbacks()