I lost two days of research tabs to a Chrome update, so I built Tabcove: automatic, local-only tab backups

Mern-Umair — Sun, 25 Oct 2026 19:38:55 +0000

Last month Chrome restarted for an update while I had two days of research open across three windows. "Restore" brought back one window. Session Buddy had eaten my saved sessions the week before. So I built the thing I wanted and published it this week.

What Tabcove does

Backs up every window on a timer (only when something changed) and keeps a window you close so you can bring it back.
Save all windows as a named session with Ctrl+Shift+S, or "save and close all" to free memory.
Restore a whole session, one window, or just the tabs you tick. Tabs open lazily, so 200 tabs come back in seconds without eating RAM.
Search across every saved session and backup.
Keeps pinned tabs and tab groups.
No account, no sync server, no analytics. Everything stays in the browser. Export to a file any time; imports OneTab and Session Buddy exports.

Free version keeps 24 hours of backups and 5 saved sessions. Pro is a one-time payment, no subscription.

The hard part: Manifest V3 service workers

MV3 kills the background service worker after about 30 seconds of inactivity, so "back up every 30 minutes" cannot be a setInterval. Tabcove uses chrome.alarms for the timer and chrome.storage.session for in-memory state, and every backup is written as a complete snapshot rather than a diff, so a worker dying mid-write never leaves a half-saved session. Restores are done in batches of windows with tabs created as discarded, which is what keeps 200-tab restores fast.

Stack: Preact + Vite + TypeScript, zero runtime dependencies, about 30 KB zipped.

DEV Community: Mern-Umair

I lost two days of research tabs to a Chrome update, so I built Tabcove: automatic, local-only tab backups

What Tabcove does

The hard part: Manifest V3 service workers

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