Cache Storage Clearing test

What this tests

This page writes a persistent tracking id into the Cache Storage API (window.caches) and reads it back. Cache Storage is an origin-scoped, disk-backed store that survives reloads and browser restarts, so it can be abused for cross-session tracking just like cookies or localStorage.

Brave's "Forget me when I close this site" (Forgetful Browsing) shield is supposed to purge all of this origin's storage once the last tab for the site is closed. This checks whether Cache Storage is included in that purge.

How to run it

1. Open Brave's Shields panel for this site and enable "Forget me when I close this site". Reload the page.
2. Click Set tracking id to write a fresh id into Cache Storage.
3. Click Get tracking id to confirm it reads back.
4. Close every tab open to this origin (and optionally quit Brave).
5. Reopen the browser, return to this page, and click Get tracking id without setting one first.

Expected behavior

• With Forgetful Browsing on: after closing the site the id should be gone. Getting the id should report no id. If the same id comes back, Cache Storage survived the close and the shield failed to clear it — a tracking leak.
• With the shield off: the id is expected to persist across restarts. This is the normal, standards-compliant behavior of Cache Storage and confirms the test actually persists state.

Run

Origin:

Cache Storage supported:

Set tracking id Get tracking id Clear tracking id

Tracking id: —