Beta 1.0.7 · Open source

Close windows.
Not by accident.

Cordon confirms before you close a protected window — a quiet, local safeguard for your open tabs.

Download latest View source
Local only No servers, no sync
Open source Fully auditable
Chromium Chrome, Edge, Brave…
Features

Small, focused, out of the way.

The essentials Cordon does well — and nothing it shouldn't.

Close confirmation

Uses Chromium's own dialog. Cancel keeps the window, Continue closes it.

Per-window arming

Protection is opt-in each session. Arm only the windows that matter.

Protect all windows

One click arms every open normal window at once. Incognito windows are skipped.

Local snapshots

Save your tabs to this device, rename them, and restore any snapshot on demand. Keep up to 30.

Search snapshots

Filter by tab title or site name — narrows both the list and the tabs inside each snapshot.

Undo delete

Removed a snapshot by mistake? A 6-second undo toast appears at the bottom of the page.

Export & import

Back up all snapshots to a JSON file, then import them back on this or another device. Import merges — nothing is overwritten.

Keyboard shortcut

Jump straight to your snapshots page with a key combo. No default assigned — set your own in Settings or chrome://extensions/shortcuts.

Light, Dark & Auto

Pick a theme in Settings, or flip it from the popup header. Auto follows your OS.

Built for privacy

No network calls, no analytics, no accounts. Everything stays on your device.

How it works

One click per window. That's it.

Arm the windows you care about — Cordon handles the rest.

STEP 01

Arm the window

Open the Cordon popup and turn on protection for the current window — or click Protect all windows to arm every open window at once.

STEP 02

Confirm once

A tiny guardian tab opens. Click anywhere on it to arm the confirmation.

STEP 03

Close with care

Chromium now asks before closing. Cancel keeps it open, Continue closes it.

Install

Up and running in under a minute.

Works on Chrome, Edge, Brave, Opera, Vivaldi, and other Chromium browsers.

  1. Download the latest release from GitHub and unzip it
  2. Open your extensions page — chrome://extensions
  3. Turn on Developer mode (top-right)
  4. Click Load unpacked and select the extension folder
  5. Pin the Cordon icon and click it to arm the current window

Download Cordon

Grab the latest beta directly from GitHub Releases. Free, open source, no sign-up.

Download v1.0.7 beta
FAQ

Common questions.

Why do I have to click once per window?
Chromium only shows the native close confirmation for a page that has had a real user gesture. Cordon's guardian tab needs one click to become eligible — no synthetic events, no workarounds.
Does my data leave my device?
No. Everything — settings, snapshots, and temporary guardian state — stays in chrome.storage.local. There are no network calls, analytics, or accounts of any kind. Export writes a JSON file to your downloads folder; import reads one back. Nothing is uploaded.
Is protection restored after I restart my browser?
No. Protection is opt-in per session, so you decide which windows to arm every time. This is deliberate: it keeps you in control and prevents surprise prompts.
Which browsers are supported?
Anything Chromium-based: Chrome, Edge, Brave, Opera, Vivaldi, Aside, and similar. Requires Chrome 116 or newer (or the equivalent in your browser).
How does export / import work?
Export writes all your snapshots to a JSON file you keep on your machine. Import reads one back and merges it with what's already there — anything that isn't a valid snapshot is skipped, and Cordon tells you how many were imported versus skipped.

Get in touch

Questions, bug reports, or ideas — reach out any time. We read everything.

Email eightey@proton.me Discord Join the server