diff --git a/.changeset/clean-cups-arrive.md b/.changeset/clean-cups-arrive.md
new file mode 100644
index 00000000..42db1c6a
--- /dev/null
+++ b/.changeset/clean-cups-arrive.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/hotkeys': patch
+---
+
+fix: detect ignored input elements across browser realms
diff --git a/packages/hotkeys/src/manager.utils.ts b/packages/hotkeys/src/manager.utils.ts
index a8c01b7b..ad60a33a 100644
--- a/packages/hotkeys/src/manager.utils.ts
+++ b/packages/hotkeys/src/manager.utils.ts
@@ -46,32 +46,36 @@ export function getDefaultIgnoreInputs(parsedHotkey: ParsedHotkey): boolean {
  * Mod+S and Escape fire when the user has tabbed to a form button.
  */
 export function isInputElement(element: EventTarget | null): boolean {
-  if (!element) {
+  if (
+    !element ||
+    !('tagName' in element) ||
+    typeof element.tagName !== 'string'
+  ) {
     return false
   }
 
-  if (element instanceof HTMLInputElement) {
-    const type = element.type.toLowerCase()
+  // Do not use instanceof here: elements from another realm (for example an
+  // iframe) have different DOM constructors than the current global object.
+  const tagName = element.tagName.toLowerCase()
+
+  if (tagName === 'input') {
+    const type =
+      'type' in element && typeof element.type === 'string'
+        ? element.type.toLowerCase()
+        : ''
     if (type === 'button' || type === 'submit' || type === 'reset') {
       return false
     }
     return true
   }
 
-  if (
-    element instanceof HTMLTextAreaElement ||
-    element instanceof HTMLSelectElement
-  ) {
+  if (tagName === 'textarea' || tagName === 'select') {
     return true
   }
 
   // Check for contenteditable elements (includes "true", "", "plaintext-only",
   // and inherited contenteditable from ancestor elements)
-  if (element instanceof HTMLElement && element.isContentEditable) {
-    return true
-  }
-
-  return false
+  return 'isContentEditable' in element && element.isContentEditable === true
 }
 
 /**
diff --git a/packages/hotkeys/tests/manager.utils.test.ts b/packages/hotkeys/tests/manager.utils.test.ts
index 073ee287..d30a9292 100644
--- a/packages/hotkeys/tests/manager.utils.test.ts
+++ b/packages/hotkeys/tests/manager.utils.test.ts
@@ -81,6 +81,35 @@ describe('manager.utils', () => {
       const div = document.createElement('div')
       expect(isInputElement(div)).toBe(false)
     })
+
+    it('should not rely on current-realm DOM constructors', () => {
+      const input = document.createElement('input')
+      input.type = 'text'
+      const button = document.createElement('input')
+      button.type = 'button'
+      const textarea = document.createElement('textarea')
+      const select = document.createElement('select')
+      const editable = document.createElement('div')
+      editable.contentEditable = 'true'
+      const regular = document.createElement('div')
+
+      vi.stubGlobal('HTMLInputElement', class {})
+      vi.stubGlobal('HTMLTextAreaElement', class {})
+      vi.stubGlobal('HTMLSelectElement', class {})
+      vi.stubGlobal('HTMLElement', class {})
+
+      try {
+        expect(input).not.toBeInstanceOf(HTMLInputElement)
+        expect(isInputElement(input)).toBe(true)
+        expect(isInputElement(button)).toBe(false)
+        expect(isInputElement(textarea)).toBe(true)
+        expect(isInputElement(select)).toBe(true)
+        expect(isInputElement(editable)).toBe(true)
+        expect(isInputElement(regular)).toBe(false)
+      } finally {
+        vi.unstubAllGlobals()
+      }
+    })
   })
 
   describe('getActiveElementForListenerTarget', () => {