Simple Firm Session Manager by kbtanvir.dev

Stop hoarding tabs. Save the session, free the memory, get on with your day.

SF Session Manager is a tab session manager built for people whose browser is
slowing down because they have too many tabs open. Unlike most session savers
that only free memory after you restore a session, SF Session Manager
discards the source window's background tabs the moment you save — your
RAM drops immediately, not later.

If you've used The Great Suspender (now defunct) and never found a clean
replacement, or if you've outgrown Tab Session Manager, OneTab, or
Auto Tab Discard for any reason — this is built to be the tool you
actually keep.



Why it exists

Modern browsers don't get slow from open tabs — they get slow from loaded
tabs. Every active tab is 30–100 MB of RAM, sometimes more. Once you cross
~50 tabs, even a 16 GB laptop starts to drag.

The fix everyone reaches for is to bookmark the tabs and close the window.
That works, but you lose multi-window context, tab groups, pinned tabs, and
the scroll position of every page. A few hours later you're hunting through
bookmarks trying to reconstruct what you had.

SF Session Manager fixes that without the bookmark dance.



What it actually does

Save = immediate memory drop. When you save a session, every non-pinned,
non-active tab in the source window is discarded on the spot. RAM usage falls
to ~5 MB per tab while the URL, title, and pinned state are preserved.

Multi-window save & restore. All your open Firefox windows are saved as a
single named session. Tab groups, pinned tabs, window state (maximized /
normal), and focus order are preserved. Restore opens the windows back in the
same shape.

Restore as sleeping (toggle). By default, restored tabs come back
discarded — they only load when you click them, so opening a 200-tab session
doesn't melt your RAM. Flip the Options toggle off if you want eager loads
instead.

Snapshot history. Every time you overwrite a session from the current
window, the prior state is kept as a snapshot. Up to 10 snapshots per
session. One-click rollback if you over-save by accident.

Tags & per-session colors. Mark sessions with free-form tags
(#work, #research, #shopping) and assign a background + foreground
color per session. The popup gets a filter chip row at the top so you can
narrow to one tag in a click.

Auto-save. Pick a target session, choose an interval (30 s / 1 min / 5
min / 15 min), and SF Session Manager periodically overwrites it from your
current window state. Each overwrite still drops a snapshot, so you can roll
back any auto-save. Great for "this is my active work session — keep it
checkpointed every minute".

Optional folder sync. On Chromium browsers, pick a local folder; on
Firefox, sync to Downloads/session-manager/. Each session writes as a
single JSON file plus a manifest. Reinstall the extension, re-import the
folder, all your sessions are back.

Export / import. Single-file JSON export and import. Move sessions
between profiles, between devices, or back them up to your own cloud.



Built for power users

• Tab hoarders who actually need 100+ tabs of context but don't want the RAM bill
• Researchers, writers, devs juggling several lines of work at once
• Anyone who's lost work to a browser crash or accidental window close
• Refugees from The Great Suspender, Tab Suspender, BarTab, or any extension
  that broke when Manifest V3 landed
• Multi-monitor setups where windows mean something (left = research, right =
  writing, etc.)

What it doesn't do (on purpose, in v1.1)

• No cloud sync between devices yet — coming in v2 (paid tier)
• No team session sharing — coming in v2
• No automatic per-domain rules — by design; you tell it what to save and when

Privacy

Local-only by default. Sessions live in your browser's chrome.storage.local.
The optional folder sync writes to a folder you pick (or Downloads/ on
Firefox) — your computer, your files. No telemetry. No accounts. No
server. The MV3 manifest lists exactly four permissions: tabs,
tabGroups, storage, downloads, plus alarms for the auto-save timer.
You can audit them in Firefox's add-ons manager.



Keywords

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manager · suspend tabs · discard tabs · sleep tabs · hibernate tabs · unload
tabs · freeze tabs · snooze tabs · lazy load tabs · tab unloader · tab
freezer · multi-window · tab groups · pinned tabs · workspace · workspace
switcher · tab snapshot · session snapshot · rollback · undo session · tab
backup · restore tabs after crash · firefox eating RAM · firefox slow many
tabs · save RAM · save memory · memory saver · RAM saver · speed up firefox
· battery saver · tab hoarder · 100 tabs open · Great Suspender alternative
· OneTab alternative · Tab Wrangler alternative · Tab Suspender alternative
· Auto Tab Discard alternative