How to Check What Permissions a Browser Extension Has

Most people skim past the permission warning when installing an extension, and never look again. But permissions can change after updates, and a small tool you installed years ago may now have access to far more than you would like. Checking is quick and worth doing.

How to view permissions in each browser

Chrome

1. Open chrome://extensions/.
2. Click Details on any extension.
3. Scroll to Permissions to see what it can access.

Chrome also lets you restrict an extension to specific sites: click Site access in the extension's Details page and choose "On specific sites" or "On click".

Firefox

1. Open about:addons.
2. Click the extension in the Extensions list.
3. Click Permissions (or the three-dot menu → Manage) to see what it can access.

Firefox lets you grant permissions on request for some extensions, so it only asks for access when the extension needs it.

Edge

1. Open edge://extensions/.
2. Click Details on any extension.
3. Scroll to Permissions (same layout as Chrome, since both are Chromium).

Opera

1. Open opera://extensions/.
2. Click an extension, then Details to see its permissions.

What to look for

As you review the list, flag anything that seems wider than the extension's purpose:

• "Read and change all your data on all websites" — the broadest access. A password manager needs this; a simple calculator does not.
• "Storage" — can save data to your browser; low risk alone, higher combined with all-site access.
• "Tabs" — can see your open tabs' URLs; normal for tab managers.
• "Cookies" — can read and modify cookies; powerful, so ask why.
• "Notifications" — can show alerts; low risk but a spam vector.
• "WebRequest" — can intercept network requests; normal for ad blockers.

For a full breakdown of each permission, see our extension permissions explained guide.

When to remove an extension

Remove (or disable) an extension if:

• You no longer use it — a forgotten extension can still watch everything you do.
• Its permission list is far wider than its purpose.
• It was last updated a long time ago and shows no signs of maintenance.
• It came from an unknown developer or a suspicious pop-up.
• You see warning signs like new ads or redirects after an update.

The habit worth keeping

Review your extension permissions every few months, and always re-check after an update. An update can silently add permissions. For the full vetting process before you install anything new, see the safe browser extensions guide.

Quick answers

Can I see an extension's permissions after install? Yes — open your browser's extensions page and the permissions are listed under Details.

What does "read all data on all websites" mean? The extension can see every page you visit and everything on it, including form fields and passwords. Grant it only to extensions that genuinely need it.

Can I limit an extension to specific sites? Chrome lets you restrict site access; Firefox supports on-request permissions for some extensions.

When should I check permissions? At install, after every update, and as part of a regular review every few months.

Sources and further reading

• Chrome: Extension permissions
• Mozilla: Manage extension permissions
• Extension permissions explained

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Written by Hassan Arshad, founder of UsefulOrbit. Last updated August 31, 2026.