diff --git a/src/renderer/src/components/browser-pane/annotate/browser-grab-toast-owner-cleanup.test.tsx b/src/renderer/src/components/browser-pane/annotate/browser-grab-toast-owner-cleanup.test.tsx
new file mode 100644
index 00000000000..7e0b616cf26
--- /dev/null
+++ b/src/renderer/src/components/browser-pane/annotate/browser-grab-toast-owner-cleanup.test.tsx
@@ -0,0 +1,400 @@
+// @vitest-environment happy-dom
+import { StrictMode, type ReactNode } from 'react'
+import { act, cleanup, renderHook } from '@testing-library/react'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import type {
+  BrowserGrabPayload,
+  BrowserExtractHoverResult
+} from '../../../../../shared/browser-grab-types'
+import { useBrowserPageGrabAnnotations } from './use-browser-page-grab-annotations'
+import { formatGrabPayloadAsText } from './GrabConfirmationSheet'
+import type { GrabModeHook } from './useGrabMode'
+
+const state = vi.hoisted(() => ({
+  recordFeatureInteraction: vi.fn(),
+  addBrowserPageAnnotation: vi.fn()
+}))
+vi.mock('@/store', () => ({
+  useAppStore: (select: (value: typeof state) => unknown) => select(state)
+}))
+vi.mock('@/i18n/i18n', () => ({ translate: (_key: string, fallback: string) => fallback }))
+
+function makePayload(): BrowserGrabPayload {
+  return {
+    page: {
+      sanitizedUrl: 'https://example.com',
+      title: 'Example',
+      viewportWidth: 1280,
+      viewportHeight: 720,
+      scrollX: 0,
+      scrollY: 0,
+      devicePixelRatio: 1,
+      capturedAt: '2026-05-15T00:00:00.000Z'
+    },
+    target: {
+      tagName: 'button',
+      selector: 'button',
+      textSnippet: 'Submit',
+      htmlSnippet: '<button>Submit</button>',
+      attributes: {},
+      accessibility: {
+        role: 'button',
+        accessibleName: 'Submit',
+        ariaLabel: null,
+        ariaLabelledBy: null
+      },
+      rectViewport: { x: 0, y: 0, width: 100, height: 40 },
+      rectPage: { x: 0, y: 0, width: 100, height: 40 },
+      computedStyles: {
+        display: 'inline-flex',
+        position: 'static',
+        width: '100px',
+        height: '40px',
+        margin: '0px',
+        padding: '0px',
+        color: 'rgb(0, 0, 0)',
+        backgroundColor: 'rgba(0, 0, 0, 0)',
+        border: '0px none',
+        borderRadius: '0px',
+        fontFamily: 'Geist',
+        fontSize: '14px',
+        fontWeight: '400',
+        lineHeight: '20px',
+        textAlign: 'center',
+        zIndex: 'auto'
+      }
+    },
+    nearbyText: [],
+    ancestorPath: [],
+    screenshot: null
+  }
+}
+
+const writes = vi.fn()
+const imageWrites = vi.fn()
+const extract = vi.fn()
+const capture = vi.fn()
+let originalApi: PropertyDescriptor | undefined
+beforeEach(() => {
+  originalApi = Object.getOwnPropertyDescriptor(window, 'api')
+  vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] })
+  writes.mockReset()
+  imageWrites.mockReset()
+  extract.mockReset()
+  capture.mockReset()
+  state.recordFeatureInteraction.mockReset()
+  Object.defineProperty(window, 'api', {
+    configurable: true,
+    value: {
+      ui: { writeClipboardText: writes, writeClipboardImage: imageWrites },
+      browser: { extractHoverPayload: extract, captureSelectionScreenshot: capture }
+    }
+  })
+})
+afterEach(() => {
+  cleanup()
+  vi.restoreAllMocks()
+  vi.useRealTimers()
+  if (originalApi) {
+    Object.defineProperty(window, 'api', originalApi)
+  } else {
+    Reflect.deleteProperty(window, 'api')
+  }
+})
+function strictWrapper({ children }: { children: ReactNode }) {
+  return <StrictMode>{children}</StrictMode>
+}
+function deferred<T>() {
+  let complete: (value: T) => void = () => {
+    throw new Error('Missing completion')
+  }
+  let fail: (error: unknown) => void = () => {
+    throw new Error('Missing rejection')
+  }
+  const promise = new Promise<T>((resolve, reject) => {
+    complete = resolve
+    fail = reject
+  })
+  return { promise, complete, fail }
+}
+function mount({
+  id = 'page-1',
+  strict = false,
+  trace = true,
+  container = document.createElement('div')
+} = {}) {
+  const bounds = trace ? vi.spyOn(container, 'getBoundingClientRect') : undefined
+  const grab: GrabModeHook = {
+    state: 'armed',
+    payload: null,
+    error: null,
+    contextMenu: false,
+    toggle: vi.fn(),
+    cancel: vi.fn(),
+    rearm: vi.fn(),
+    exit: vi.fn()
+  }
+  const containerRef = { current: container }
+  const webviewRef = { current: null }
+  const view = renderHook(
+    ({ target }) =>
+      useBrowserPageGrabAnnotations({
+        browserTabId: id,
+        toolTargetId: target,
+        isActive: true,
+        grab,
+        containerRef,
+        webviewRef,
+        setBrowserOverlayViewport: vi.fn(),
+        browserAnnotationsLength: 0,
+        setBrowserAnnotationTrayOpen: vi.fn()
+      }),
+    { initialProps: { target: id }, ...(strict ? { wrapper: strictWrapper } : {}) }
+  )
+  return { view, bounds, reference: new WeakRef(container), grab }
+}
+const screenshot = {
+  mimeType: 'image/png',
+  dataUrl: 'data:image/png;base64,Ynl0ZXM=',
+  width: 100,
+  height: 40
+} as const
+describe('browser grab toast owner', () => {
+  it.each(['miss', 'reject'] as const)(
+    'releases sixty-four closed shortcut %s owners',
+    async (outcome) => {
+      const requests = Array.from({ length: 64 }, () => deferred<BrowserExtractHoverResult>())
+      let index = 0
+      extract.mockImplementation(() => requests[index++].promise)
+      const bounds: ReturnType<typeof mount>['bounds'][] = []
+      for (let owner = 0; owner < 64; owner++) {
+        const mounted = mount({ id: `page${owner}` })
+        bounds.push(mounted.bounds)
+        act(() => mounted.view.result.current.handleGrabActionShortcut('c'))
+        mounted.view.unmount()
+      }
+      expect(extract.mock.calls).toEqual(
+        Array.from({ length: 64 }, (_, owner) => [{ browserPageId: `page${owner}` }])
+      )
+      expect(vi.getTimerCount()).toBe(0)
+      await act(async () => {
+        for (const request of requests) {
+          if (outcome === 'miss') {
+            request.complete({ ok: false, reason: 'not-ready' })
+          } else {
+            request.fail(new Error('Guest destroyed'))
+          }
+        }
+        await Promise.resolve()
+      })
+      expect(writes).not.toHaveBeenCalled()
+      expect(imageWrites).not.toHaveBeenCalled()
+      expect(state.recordFeatureInteraction).not.toHaveBeenCalled()
+      expect(bounds.reduce((total, bound) => total + (bound?.mock.calls.length ?? 0), 0)).toBe(0)
+      expect(vi.getTimerCount()).toBe(0)
+    }
+  )
+  it.each(['c', 's'] as const)(
+    'finishes late requested %s delivery without closed presentation',
+    async (key) => {
+      const request = deferred<BrowserExtractHoverResult>()
+      const payload = makePayload()
+      extract.mockReturnValue(request.promise)
+      capture.mockResolvedValue({ ok: true, screenshot })
+      const { view, bounds } = mount()
+      act(() => view.result.current.handleGrabActionShortcut(key))
+      view.unmount()
+      await act(async () => {
+        request.complete({ ok: true, payload })
+        await Promise.resolve()
+      })
+      if (key === 'c') {
+        expect(writes.mock.calls).toEqual([[formatGrabPayloadAsText(payload)]])
+      } else {
+        expect(capture.mock.calls).toEqual([
+          [{ browserPageId: 'page-1', rect: payload.target.rectViewport }]
+        ])
+        expect(imageWrites.mock.calls).toEqual([[screenshot.dataUrl]])
+        expect(payload.screenshot).toBe(screenshot)
+      }
+      expect(state.recordFeatureInteraction.mock.calls).toEqual([['browser-grab']])
+      expect(bounds).not.toHaveBeenCalled()
+      expect(vi.getTimerCount()).toBe(0)
+    }
+  )
+  it.each(['c', 's'] as const)(
+    'preserves complete live %s toast and exact two-second lifetime',
+    async (key) => {
+      const payload = makePayload()
+      extract.mockResolvedValue({ ok: true, payload })
+      capture.mockResolvedValue({ ok: true, screenshot })
+      const { view, bounds, grab } = mount({ strict: true })
+      await act(async () => {
+        view.result.current.handleGrabActionShortcut(key)
+        await Promise.resolve()
+      })
+      expect(writes.mock.calls).toEqual(key === 'c' ? [[formatGrabPayloadAsText(payload)]] : [])
+      expect(imageWrites.mock.calls).toEqual(key === 's' ? [[screenshot.dataUrl]] : [])
+      expect(state.recordFeatureInteraction.mock.calls).toEqual([['browser-grab']])
+      expect(view.result.current.grabToast).toEqual({
+        message: key === 'c' ? 'Copied' : 'Screenshotted',
+        type: 'success',
+        x: 50,
+        y: 0,
+        below: false,
+        payload
+      })
+      expect(bounds).toHaveBeenCalledTimes(1)
+      expect(vi.getTimerCount()).toBe(1)
+      act(() => vi.advanceTimersByTime(1999))
+      expect(view.result.current.grabToast?.type).toBe('success')
+      act(() => vi.advanceTimersByTime(1))
+      expect(view.result.current.grabToast).toBeNull()
+      expect(grab.rearm).not.toHaveBeenCalled()
+      expect(vi.getTimerCount()).toBe(0)
+    }
+  )
+  it.each(['miss', 'reject', 'screenshot-reject'] as const)(
+    'preserves live %s feedback and cleanup',
+    async (outcome) => {
+      const payload = makePayload()
+      if (outcome === 'miss') {
+        extract.mockResolvedValue({ ok: false, reason: 'not-ready' })
+      } else if (outcome === 'reject') {
+        extract.mockRejectedValue(new Error('Guest destroyed'))
+      } else {
+        extract.mockResolvedValue({ ok: true, payload })
+        capture.mockRejectedValue(new Error('Screenshot failed'))
+      }
+      const { view, bounds } = mount()
+      await act(async () => {
+        view.result.current.handleGrabActionShortcut(outcome === 'screenshot-reject' ? 's' : 'c')
+        await Promise.resolve()
+      })
+      expect(view.result.current.grabToast?.message).toBe(
+        outcome === 'miss'
+          ? 'No element hovered'
+          : outcome === 'reject'
+            ? 'Could not read the hovered element'
+            : 'No screenshot available'
+      )
+      expect(view.result.current.grabToast?.type).toBe('error')
+      expect(writes).not.toHaveBeenCalled()
+      expect(imageWrites).not.toHaveBeenCalled()
+      expect(state.recordFeatureInteraction).not.toHaveBeenCalled()
+      expect(bounds).toHaveBeenCalledTimes(1)
+      expect(vi.getTimerCount()).toBe(1)
+      view.unmount()
+      expect(vi.getTimerCount()).toBe(0)
+    }
+  )
+  it('keeps a same-DOM replacement timer after a closed StrictMode owner settles', async () => {
+    const request = deferred<BrowserExtractHoverResult>()
+    const payload = makePayload()
+    const container = document.createElement('div')
+    extract.mockReturnValueOnce(request.promise).mockResolvedValueOnce({ ok: true, payload })
+    const old = mount({ strict: true, container })
+    act(() => old.view.result.current.handleGrabActionShortcut('c'))
+    old.view.unmount()
+    const next = mount({ id: 'page-2', strict: true, container })
+    await act(async () => {
+      next.view.result.current.handleGrabActionShortcut('c')
+      await Promise.resolve()
+    })
+    const replacementToast = next.view.result.current.grabToast
+    await act(async () => {
+      request.complete({ ok: true, payload })
+      await Promise.resolve()
+    })
+    expect(writes.mock.calls).toEqual([
+      [formatGrabPayloadAsText(payload)],
+      [formatGrabPayloadAsText(payload)]
+    ])
+    expect(state.recordFeatureInteraction).toHaveBeenCalledTimes(2)
+    expect(next.view.result.current.grabToast).toBe(replacementToast)
+    expect(next.bounds).toHaveBeenCalledTimes(1)
+    expect(vi.getTimerCount()).toBe(1)
+    act(() => vi.advanceTimersByTime(2000))
+    expect(next.view.result.current.grabToast).toBeNull()
+    expect(vi.getTimerCount()).toBe(0)
+  })
+  it.each(['clipboard', 'interaction'] as const)(
+    'honors reentrant cleanup during %s delivery',
+    async (point) => {
+      const payload = makePayload()
+      extract.mockResolvedValue({ ok: true, payload })
+      const { view, bounds } = mount()
+      if (point === 'clipboard') {
+        writes.mockImplementationOnce(() => view.unmount())
+      } else {
+        state.recordFeatureInteraction.mockImplementationOnce(() => view.unmount())
+      }
+      await act(async () => {
+        view.result.current.handleGrabActionShortcut('c')
+        await Promise.resolve()
+      })
+      expect(writes.mock.calls).toEqual([[formatGrabPayloadAsText(payload)]])
+      expect(state.recordFeatureInteraction.mock.calls).toEqual([['browser-grab']])
+      expect(bounds).not.toHaveBeenCalled()
+      expect(vi.getTimerCount()).toBe(0)
+    }
+  )
+  it('preserves latest target reads and screenshot completion after cleanup', async () => {
+    const extraction = deferred<BrowserExtractHoverResult>()
+    const image = deferred<{ ok: true; screenshot: typeof screenshot }>()
+    const payload = makePayload()
+    extract.mockReturnValue(extraction.promise)
+    capture.mockReturnValue(image.promise)
+    const { view, bounds } = mount()
+    act(() => view.result.current.handleGrabActionShortcut('s'))
+    view.rerender({ target: 'recovered-target' })
+    await act(async () => {
+      extraction.complete({ ok: true, payload })
+      await Promise.resolve()
+    })
+    expect(extract.mock.calls).toEqual([[{ browserPageId: 'page-1' }]])
+    expect(capture.mock.calls).toEqual([
+      [{ browserPageId: 'recovered-target', rect: payload.target.rectViewport }]
+    ])
+    view.unmount()
+    await act(async () => {
+      image.complete({ ok: true, screenshot })
+      await Promise.resolve()
+    })
+    expect(imageWrites.mock.calls).toEqual([[screenshot.dataUrl]])
+    expect(state.recordFeatureInteraction.mock.calls).toEqual([['browser-grab']])
+    expect(payload.screenshot).toBe(screenshot)
+    expect(bounds).not.toHaveBeenCalled()
+    expect(vi.getTimerCount()).toBe(0)
+  })
+  it('releases closed container references after settled shortcuts', async () => {
+    const request = deferred<BrowserExtractHoverResult>()
+    extract.mockReturnValue(request.promise)
+    function closeOwners() {
+      const references: WeakRef<HTMLElement>[] = []
+      for (let owner = 0; owner < 64; owner++) {
+        const { view, reference } = mount({ id: `page${owner}`, trace: false })
+        references.push(reference)
+        act(() => view.result.current.handleGrabActionShortcut('c'))
+        view.unmount()
+      }
+      return references
+    }
+    const references = closeOwners()
+    cleanup()
+    await act(async () => {
+      request.complete({ ok: false, reason: 'not-ready' })
+      await Promise.resolve()
+    })
+    expect(extract).toHaveBeenCalledTimes(64)
+    expect(writes).not.toHaveBeenCalled()
+    if (typeof globalThis.gc !== 'function') {
+      throw new Error('The runner must enable forced GC')
+    }
+    await new Promise<void>((resolve) => setImmediate(resolve))
+    globalThis.gc()
+    globalThis.gc()
+    expect(references.filter((reference) => reference.deref()).length).toBe(0)
+    expect(vi.getTimerCount()).toBe(0)
+  })
+})
diff --git a/src/renderer/src/components/browser-pane/annotate/use-browser-page-grab-annotations.ts b/src/renderer/src/components/browser-pane/annotate/use-browser-page-grab-annotations.ts
index 2f6cdaeb33a..16225019b31 100644
--- a/src/renderer/src/components/browser-pane/annotate/use-browser-page-grab-annotations.ts
+++ b/src/renderer/src/components/browser-pane/annotate/use-browser-page-grab-annotations.ts
@@ -9,6 +9,7 @@ import {
   type SetStateAction
 } from 'react'
 import { translate } from '@/i18n/i18n'
+import { useMountedRef } from '@/hooks/useMountedRef'
 import { useAppStore } from '@/store'
 import type {
   BrowserAnnotationIntent,
@@ -88,6 +89,7 @@ export function useBrowserPageGrabAnnotations({
   handleCancelPendingBrowserAnnotation: () => void
   handleGrabActionShortcut: (key: 'c' | 's') => void
 } {
+  const mountedRef = useMountedRef()
   const toolTargetIdRef = useRef(toolTargetId)
   const grabToastTimerRef = useRef<ReturnType<typeof setTimeout>>(undefined)
   const [grabIntent, setGrabIntent] = useState<GrabIntent>('copy')
@@ -132,6 +134,9 @@ export function useBrowserPageGrabAnnotations({
 
   const showGrabToast = useCallback(
     (message: string, type: 'success' | 'error', payload?: BrowserGrabPayload | null) => {
+      if (!mountedRef.current) {
+        return
+      }
       let x = 0
       let y = 0
       let below = true
@@ -157,7 +162,7 @@ export function useBrowserPageGrabAnnotations({
       setGrabToast({ message, type, x, y, below, payload: payload ?? null })
       grabToastTimerRef.current = setTimeout(() => dismissGrabToast(), 2000)
     },
-    [containerRef, dismissGrabToast, webviewRef]
+    [containerRef, dismissGrabToast, mountedRef, webviewRef]
   )
 
   // Why: the same in-guest picker powers two flows — Cmd/Ctrl+C copies, the toolbar action creates a pending annotation.