No. Chrome's documentation says extension storage is not cleared when a user clears browsing data. Whatever an extension saved can remain after you wipe cookies and history. To remove it, you remove the extension. Incognito access is a separate setting that you control per extension.
What the documentation says
Chrome's extension storage guidance states that extension storage is not cleared when a user clears browsing data. It is shared across the extension's origin, including the service worker, extension pages and offscreen documents. In content scripts, web storage calls reach the host page's storage, not the extension's.
Storage is also subject to quotas and can be evicted under memory pressure unless the developer requests protections.
Why this matters
People clear browsing data to reset tracking. For ordinary sites, that works. For extensions it may not. An extension could still hold:
- Settings and preferences.
- Tokens or identifiers it stored for its own service.
- Lists, notes or cached results.
That is not automatically a problem, since many extensions store only settings. It becomes a problem when sensitive data is stored and you assumed clearing history would remove it.
How to remove an extension's data
Remove the extension. Right click its toolbar icon and choose Remove from Chrome, or use Manage extensions. This post does not cover the exact data left behind in each browser after removal, so check vendor documentation for specifics. If you re install later, treat it as a fresh start and review permissions again.
Incognito and local files
By default extensions do not run in incognito. Chrome's help describes turning on an incognito option in an extension's Details. Chrome's developer documentation adds that file URL access also needs the user to enable it on the extension's details page.
So two access paths are opt in by the user:
- Incognito windows.
- Local files.
Leave both off unless an extension needs them. A tool that asks you to enable file access should explain why in its listing.
A short checklist
Think of an extension the way you would a small app on your computer. It has its own storage, its own settings and its own life, and the browser's clear history button is not an uninstaller. If you would not leave a file on a shared computer, do not leave data in an extension you no longer trust.
- Do not treat clearing browsing data as clearing extension data.
- Remove extensions you do not use.
- Keep incognito access off by default.
- Avoid giving extensions secrets you would not store in a note.
- Review what the privacy section says about retention.
More on routine review in the five minute audit.
Quick check
Does a password manager extension store passwords locally?
This post cannot say how any given product stores data. Check the vendor's documentation.
Does Firefox behave the same way?
I did not confirm this from Mozilla's documentation. Check Mozilla's guidance before assuming.
Sources
- Storage and cookies (Chrome for Developers)
- Manage Chrome extensions (Google Chrome Help)
- Declare permissions (Chrome for Developers)
Last reviewed: 19 October 2026.
