I built a Firefox/Chrome extension that monitors the health and safety of your browser bookmarks entirely locally. No accounts, no servers, no analytics. Any changes to your native browser bookmarks (or the same bookmarks within the extension) are instantly synced; deletions include a 5-second undo window.

It checks for:

dead/parked links

suspicious redirects

changes in domain behavior

duplicates

optional integration for user-supplied API keys for VirusTotal / Google Safe Browsing / Yandex

It also keeps 7-day cached results and alerts you if a previously safe bookmark becomes suspicious. All analysis runs on-device and the code is fully open source.

Firefox: https://github.com/AbsoluteXYZero/Bookmark-Manager-Zero-Fire...

https://addons.mozilla.org/en-US/firefox/addon/bookmark-mana...

Chrome: https://github.com/AbsoluteXYZero/Bookmark-Manager-Zero-Chro...

https://chromewebstore.google.com/detail/bookmark-manager-ze...

Chrome Web Store reviews lag behind, so the Chrome version is currently one release behind Firefox.

Known limitations: relies partially on external plaintext blocklists → possible false positives/negatives. Preview images are fetched via the public mShots screenshot service (nothing else leaves the browser).

Feedback appreciated.