diff --git a/src/browser/webapi/CData.zig b/src/browser/webapi/CData.zig
index 0d2bc53e6..b75c4fae1 100644
--- a/src/browser/webapi/CData.zig
+++ b/src/browser/webapi/CData.zig
@@ -135,6 +135,10 @@ pub fn getLength(self: *const CData) usize {
     return self._data.len;
 }
 
+pub fn isEqualNode(self: *const CData, other: *const CData) bool {
+    return std.mem.eql(u8, self.getData(), other.getData());
+}
+
 pub fn appendData(self: *CData, data: []const u8, page: *Page) !void {
     const new_data = try std.mem.concat(page.arena, u8, &.{ self._data, data });
     try self.setData(new_data, page);
@@ -256,6 +260,7 @@ pub const JsApi = struct {
     pub const data = bridge.accessor(CData.getData, CData.setData, .{});
     pub const length = bridge.accessor(CData.getLength, null, .{});
 
+    pub const isEqualNode = bridge.function(CData.isEqualNode, .{});
     pub const appendData = bridge.function(CData.appendData, .{});
     pub const deleteData = bridge.function(CData.deleteData, .{ .dom_exception = true });
     pub const insertData = bridge.function(CData.insertData, .{ .dom_exception = true });
diff --git a/src/browser/webapi/Element.zig b/src/browser/webapi/Element.zig
index 32a2b18a5..03ec1e410 100644
--- a/src/browser/webapi/Element.zig
+++ b/src/browser/webapi/Element.zig
@@ -117,6 +117,57 @@ pub fn className(self: *const Element) []const u8 {
     };
 }
 
+/// TODO: localName and prefix comparison.
+pub fn isEqualNode(self: *Element, other: *Element) bool {
+    const self_tag = self.getTagNameDump();
+    const other_tag = other.getTagNameDump();
+    // Compare namespaces and tags.
+    const dirty = self._namespace != other._namespace or !std.mem.eql(u8, self_tag, other_tag);
+    if (dirty) {
+        return false;
+    }
+
+    // Compare attributes.
+    {
+        var self_iter = self.attributeIterator();
+        var other_iter = other.attributeIterator();
+        var self_count: usize = 0;
+        var other_count: usize = 0;
+        while (self_iter.next()) |a1| : (self_count += 1) {
+            const a2 = other_iter.next() orelse return false;
+            other_count += 1;
+            if (a1._name.eql(a2._name) and a1._value.eql(a2._value)) {
+                continue;
+            }
+
+            return false;
+        }
+
+        // Make sure both have equal number of attribs.
+        if (self_count != other_count) {
+            return false;
+        }
+    }
+
+    // Compare children.
+    var self_iter = self.asNode().childrenIterator();
+    var other_iter = other.asNode().childrenIterator();
+    var self_count: usize = 0;
+    var other_count: usize = 0;
+    while (self_iter.next()) |self_node| : (self_count += 1) {
+        const other_node = other_iter.next() orelse return false;
+        other_count += 1;
+        if (self_node.isEqualNode(other_node)) {
+            continue;
+        }
+
+        return false;
+    }
+
+    // Make sure both have equal number of children.
+    return self_count == other_count;
+}
+
 pub fn getTagNameLower(self: *const Element) []const u8 {
     switch (self._type) {
         .html => |he| switch (he._type) {
@@ -1034,6 +1085,7 @@ pub const JsApi = struct {
     pub const removeAttributeNode = bridge.function(Element.removeAttributeNode, .{ .dom_exception = true });
     pub const shadowRoot = bridge.accessor(Element.getShadowRoot, null, .{});
     pub const attachShadow = bridge.function(_attachShadow, .{ .dom_exception = true });
+    pub const isEqualNode = bridge.function(Element.isEqualNode, .{});
 
     const ShadowRootInit = struct {
         mode: []const u8,
diff --git a/src/browser/webapi/Node.zig b/src/browser/webapi/Node.zig
index ef6de4a7d..a9c4d9eef 100644
--- a/src/browser/webapi/Node.zig
+++ b/src/browser/webapi/Node.zig
@@ -236,6 +236,27 @@ pub fn nodeType(self: *const Node) u8 {
     };
 }
 
+pub fn isEqualNode(self: *Node, other: *Node) bool {
+    // Make sure types match.
+    if (self.nodeType() != other.nodeType()) {
+        return false;
+    }
+
+    // TODO: Compare `localName` and prefix.
+    return switch (self._type) {
+        .element => self.as(Element).isEqualNode(other.as(Element)),
+        .attribute => self.as(Element.Attribute).isEqualNode(other.as(Element.Attribute)),
+        .cdata => self.as(CData).isEqualNode(other.as(CData)),
+        else => {
+            log.warn(.browser, "not implemented", .{
+                .type = self._type,
+                .feature = "Node.isEqualNode",
+            });
+            return false;
+        },
+    };
+}
+
 pub fn isInShadowTree(self: *Node) bool {
     var node = self._parent;
     while (node) |n| {
@@ -760,6 +781,7 @@ pub const JsApi = struct {
     pub const cloneNode = bridge.function(Node.cloneNode, .{ .dom_exception = true });
     pub const compareDocumentPosition = bridge.function(Node.compareDocumentPosition, .{});
     pub const getRootNode = bridge.function(Node.getRootNode, .{});
+    pub const isEqualNode = bridge.function(Node.isEqualNode, .{});
 
     pub const toString = bridge.function(_toString, .{});
     fn _toString(self: *const Node) []const u8 {
diff --git a/src/browser/webapi/element/Attribute.zig b/src/browser/webapi/element/Attribute.zig
index b5d45a612..0930af73f 100644
--- a/src/browser/webapi/element/Attribute.zig
+++ b/src/browser/webapi/element/Attribute.zig
@@ -78,6 +78,10 @@ pub fn getOwnerElement(self: *const Attribute) ?*Element {
     return self._element;
 }
 
+pub fn isEqualNode(self: *const Attribute, other: *const Attribute) bool {
+    return std.mem.eql(u8, self.getName(), other.getName()) and std.mem.eql(u8, self.getValue(), other.getValue());
+}
+
 pub const JsApi = struct {
     pub const bridge = js.Bridge(Attribute);
 
@@ -96,6 +100,8 @@ pub const JsApi = struct {
     pub const value = bridge.accessor(Attribute.getValue, null, .{});
     pub const namespaceURI = bridge.accessor(Attribute.getNamespaceURI, null, .{});
     pub const ownerElement = bridge.accessor(Attribute.getOwnerElement, null, .{});
+
+    pub const isEqualNode = bridge.function(Attribute.isEqualNode, .{});
 };
 
 // This is what an Element references. It isn't exposed to JavaScript. In