Local Suspender

Privacy-first Chrome extension that suspends inactive tabs to free memory and CPU. All data stays on your device with AES-256-GCM encryption.

Features

• Automatically suspends tabs after a configurable idle period
• Two suspension methods: native tab discard or a parked page
• AES-256-GCM encryption of session state with optional passkey protection
• Encrypted session snapshots for tab recovery
• Whitelist patterns to exclude specific sites
• Passkey-wrapped cloud key backup via Chrome Sync (optional)
• Zero network calls, zero external dependencies
• Manifest V3, vanilla JavaScript

Install from source

1. Clone this repository
2. Open chrome://extensions and enable Developer mode
3. Click Load unpacked and select the extension/ directory

Package for distribution

npm install
npm run package

This creates dist/local-suspender-<version>.zip.

Project structure

extension/
  background.js     Service worker (core logic, encryption, state)
  encryption.js     AES-256-GCM key management and wrapping
  settings.js       Settings schema and persistence
  session.js        chrome.storage.session wrapper
  logger.js         Structured logging to storage
  popup.html/js/css Toolbar popup UI
  options.html/js/css Options page UI
  suspended.html/js/css Parked tab page
  manifest.json     Chrome extension manifest (MV3)
scripts/
  package-extension.mjs  Packaging script

Configuration

Setting	Default	Description
Auto-suspend after	30 min	Idle threshold before suspension
Exclude active tab	Yes	Never suspend the focused tab
Exclude pinned tabs	Yes	Never suspend pinned tabs
Exclude audible tabs	Yes	Never suspend tabs playing audio
Unsuspend method	On focus	Auto-restore when tab is activated
Whitelist	Empty	URL patterns to never suspend
Cloud key backup	Off	Sync passkey-wrapped encryption key via Chrome Sync

License

MIT