Installation

Better Tab Unload is not on the Chrome Web Store. You load it as an unpacked extension from a local checkout.

Requirements

• Chrome, Edge, Brave, or another Chromium browser with Manifest V3 support.
• Nothing to compile. The extension is plain JavaScript, HTML, and CSS with no build step and no runtime dependencies.
• Node.js is only needed if you want to build the documentation site or run the syntax checks.

Load the extension

1. Clone the repository:

   git clone https://github.com/rennerdo30/better-tab-unload.git

2. Open chrome://extensions.

3. Enable Developer mode (top right).

4. Click Load unpacked and select this project folder — the directory containing manifest.json.

Chrome only reads the files referenced by manifest.json. The docs/ and .github/ directories in the repository are ignored by the browser, so you can load the checkout as-is.

Permissions it asks for

manifest.json requests the following, and each one is load-bearing:

Permission	Why it is needed
tabs	Read tab state (discarded, status, url, pendingUrl) and detect when a discarded tab is reactivated.
activeTab	Capture the visible pixels of the active tab.
scripting	Re-inject the content script into already-open tabs after the service worker starts, since content scripts are not retro-injected on install or browser restart.
host_permissions: <all_urls>	captureVisibleTab and the overlay must work on any site you visit, not a fixed allowlist.

Verify it works

1. Open a normal website and let it fully load.
2. Switch to another tab, and wait a moment so the screenshot capture can run.
3. Force the first tab to be discarded: open chrome://discards, find the tab, and click Urgent Discard. (Waiting for real memory pressure also works, but is slow.)
4. Switch back to the discarded tab. You should briefly see the previous rendering of the page instead of a blank white screen.

To confirm screenshots are actually being stored, open the extension’s options page (Details → Extension options on chrome://extensions). It lists every stored screenshot with its URL, capture time, and an approximate total storage size.

If the placeholder never appears, see Troubleshooting.

Syntax checks

There is no test suite. The repository ships a syntax check for the extension sources:

npm run check

which is equivalent to:

node --check background.js
node --check content.js
node --check restore.js
node --check storage.js
node --check options.js