Browser Storage Test

Browser Storage Test shows how much a website may keep in your browser and whether each kind of storage works. The large number is this site’s quota on this device — the most the browser will let one site store — with how much this site is using now, as the browser reports it. Below, each kind of storage is checked by really using it: a value is written to local storage and session storage and read back, a small IndexedDB database is opened and deleted, cache storage (what lets sites work offline) and the private file system are opened, and cookies are checked. Each says Works, Not available, or Blocked. Last, it says whether the browser has promised to keep this site’s data, or may clear it when the disk runs low. It is useful when a web app forgets your settings, will not work offline, or says storage is full.

1. Open the page; the checks run by themselves in a moment.
2. Read the quota and the note under it: a quota of a few hundred megabytes usually means a private window.
3. Look down the list for anything Blocked — that is the storage a forgetful site cannot use.
4. Reload after changing a privacy setting to check again.

• Quotas are set by the browser from your free disk space and change as the disk fills, so the number moves. Chrome and Edge allow a site up to about 60% of the disk, Firefox about 10% (more once data is kept for good), and Safari a share that depends on the device.
• Usage is the browser’s estimate and is often rounded or padded on purpose, for privacy; it may not match the size of files you think are stored.
• Safari may delete a site’s storage after seven days without a visit, whatever the quota, unless the site is added to the Home Screen.
• Third-party cookies and storage inside other sites’ frames are a separate matter, often blocked by default; this page checks this site’s own storage only.
• A Blocked result says storage failed, not exactly why: privacy settings, extensions, a private window and a full disk all look the same to a page.
• Every check runs in your browser. The test value written to local and session storage, and the test database, are removed the moment they have been read back; nothing is sent or kept. The quota and usage are this site’s only — no page can see how much other sites store.

Check whether local storage or cookies say Blocked here. If they do, the browser’s privacy settings, an extension, or a private window is stopping the site saving anything. Allow cookies and site data for that site, or use a normal window.

The large number at the top is the answer for this site on this device. It is usually many gigabytes on a computer with free space, and much less in a private window.

Local storage keeps small pieces of text, such as a theme or a setting. IndexedDB is a database for larger data — saved documents, offline maps, music. Both stay until you clear the site’s data.

In the browser’s site settings (the icon left of the address), choose to clear the site’s data or cookies. This removes its local storage, IndexedDB and cache together.