Artek Tab Vault troch Artem Guliaev

Artek Tab Vault fixes two of the most common Firefox pain points: losing every
open tab after a crash or update, and Firefox slowly eating your RAM with
dozens of tabs open.

It is free and open source (MIT). Source and issue tracker:
https://github.com/itsuppartem/artek-tab-vault

WHAT IT DOES

Independent session backup
- Takes a rolling snapshot of every open window and tab on an interval you
control, completely independent of Firefox's own session restore (which
can and does fail on crash or update).
- Keeps a configurable number of past snapshots, not just the last one, so a
single bad save can't wipe your history. Never persists a corrupted/empty
snapshot over a good one.
- Optional size cap (MB) for the whole backup history on top of the snapshot
count limit, with three ready-made presets (compact/balanced/archivist).
Every time old snapshots actually get trimmed - or a snapshot gets skipped
as empty/corrupted - it's recorded in a visible log in settings, so
retention is never a silent surprise.
- Captures and restores native Firefox tab groups (name, color, collapsed
state) where the browser supports the tabGroups API.
- One-click restore of any snapshot, plus manual "backup now".
- Restore into a new window (default) or straight into your current window,
so you're not doubling up memory with duplicate windows. Pinned tabs stay
pinned.
- Export/import snapshots as JSON. Import also tolerates plain URL lists and
a few common export shapes from other tab/session managers, skipping only
the individual entries it can't understand instead of failing outright.
- Detects a likely crash/unclean shutdown on the next Firefox launch and
notifies you to restore the last backup. The prompt does not fire on
add-on install, update, or reload, and it does not repeat after you have
already been notified.

Guardian: automatic memory relief
- Automatically discards (unloads) tabs that have been idle for a
configurable number of minutes, freeing RAM and CPU without closing them.
- Never touches the active tab, pinned tabs, tabs playing audio, or (by
default) a tab with an unsubmitted form - so you don't lose typed input.
The unsaved-form flag clears on reset, submit, and in-page / SPA
navigation, so a leftover form does not block discard forever.
- Never discards tabs with in-page video or audio that is playing, or paused
with progress. Empty never-played media is not protected.
- Never discards known media hosts (YouTube, Vimeo, Twitch, Netflix,
SoundCloud, Spotify, Apple Music, Yandex Music, Dailymotion) even if the
page has not been probed yet.
- Domain whitelist: tell it to never discard specific sites (e.g. your email,
a long-running dashboard).
- Smart tab activation: when the active tab is closed, immediately hands
focus to the nearest already-loaded tab instead of leaving you staring at
a discarded neighbor reloading itself.
- Marks discarded tabs right in Firefox's own tab strip/sidebar with a
configurable title prefix (default "💤 ") - so you can tell at a glance
without opening the popup.
- "Discard all except current" one-click button and keyboard shortcut.
- Popup shows every tab in the current window with a clear
active/loaded/discarded indicator, plus a toolbar badge with the total
discarded count.
- Every button (discard, backup, restore, save, reset, export/import,
presets) gives instant visual confirmation - a press animation plus a
brief "✓ done" flash and a text summary - so you always know an action
actually went through.
- Localized UI: English, Russian, Kazakh, Ukrainian, Belarusian, and
Serbian, following Firefox's language setting.

WHAT IT DOESN'T DO (known limitations)
- Firefox's extension APIs don't expose real per-tab RAM usage, so discarding
decisions are based on idle time, not measured memory, and the popup shows
discarded/loaded state rather than a byte count.
- Restoring a snapshot reopens tabs by URL; it doesn't restore in-page
browsing history, scroll position, or unsaved form state from before the
backup was taken.
- Firefox gives extensions no way to cancel the reload it starts when it
auto-activates a discarded tab; "smart tab activation" moves your focus off
it immediately afterwards, it can't prevent the reload from starting.

PERMISSIONS
- tabs / storage / alarms / idle / notifications / tabGroups - used strictly
for the backup, guardian, and tab-group-restore features above.
- unlimitedStorage - lets the local backup history grow past the browser's
default ~5-10MB local-storage quota when you raise the size limit above the
default; still fully local, nothing is uploaded anywhere.
- Access to all sites - used on-device only: (1) detect an unsubmitted form
or in-use video/audio so Guardian can skip that tab (only true/false flags
are kept; page contents are never stored or sent); (2) rewrite a tab title
(e.g. adding "💤 ") right before discarding it. Nothing is transmitted.
- No browsing data ever leaves your machine. No telemetry.

OPEN SOURCE
Free and open source under the MIT License.
Source: https://github.com/itsuppartem/artek-tab-vault
Issues: https://github.com/itsuppartem/artek-tab-vault/issues

Feedback and bug reports are welcome on GitHub Issues or via a review on
this page - please describe the problem instead of only leaving a low
rating, so it can actually get fixed.