Drowzy

The open-source tab suspender for Chrome.
Auto-suspend inactive tabs. Save up to 80% memory. No tracking, no servers, no nonsense.

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Why Drowzy?

Most tab suspenders replace your tabs with custom placeholder pages. If the extension breaks, gets removed, or Chrome updates -- your tabs are gone.

Drowzy is different. It uses Chrome's built-in chrome.tabs.discard() API, which means:

• Suspended tabs are managed by Chrome itself -- they survive restarts, crashes, and even uninstalling Drowzy
• Tabs keep their full history, scroll position, and form data
• No custom pages, no redirects, no chrome-extension:// URLs in your tab bar
• Waking a tab is instant -- just click it

On top of that, Drowzy is fully open source, collects zero data, and runs entirely in your browser. No servers, no analytics, no accounts. Your tabs are yours.

Features

Core

• Auto-suspend inactive tabs after a configurable timer (5 min -- 4 hours, or manual only)
• Smart protection -- pinned tabs, audio-playing tabs, and tabs with unsaved form data are never suspended
• Whitelist sites with pattern matching and wildcards (e.g., github.com/ml3dev/*)
• Keyboard shortcuts -- Alt+S suspend current, Alt+Shift+S suspend others, Alt+W wake all
• Context menu -- right-click any page for quick suspend options

Sessions & Organization

• Save and restore sessions -- bookmark your entire window state and reopen it later
• Tab group support -- session restore preserves tab groups with names and colors
• Close duplicate tabs -- one click to deduplicate your window
• Tab search -- filter your tab list by title or URL
• Export -- copy your tab list or sessions as JSON for backup

Polish

• Dark and light theme -- toggle in the header, preference is saved
• Side panel -- pin Drowzy to Chrome's side panel for a persistent full-height view
• 57 languages -- UI automatically matches your browser language
• Suspend indicator -- optional [zzz] prefix on suspended tab titles
• Suspend warning -- brief notification before a tab is auto-suspended
• Stats dashboard -- track how many tabs you've suspended and how much memory you've saved
• Review prompt -- a gentle, dismissable nudge after 50+ suspensions (never annoying, never repeated)

How It Works

Tab inactive for 30 min ──> Drowzy calls chrome.tabs.discard()
                                        │
                                        ▼
                              Chrome unloads the tab
                              (0 MB RAM, tab stays in bar)
                                        │
                                        ▼
                              User clicks tab ──> Chrome reloads it

Drowzy runs a lightweight alarm every 60 seconds. It checks each tab's last-active timestamp and suspends any that exceed your chosen threshold. Protected tabs (pinned, audible, whitelisted, active, or containing forms) are always skipped. That's it -- no background pages, no content scripts running on every page, no idle CPU usage.

Comparison

	Drowzy	Marvellous Suspender	Tab Suspender Pro	Chrome Memory Saver
Open source	Yes	Yes	No	N/A
Native discard API	Yes	No	No	Yes
Zero tracking	Yes	Yes	No	Yes
Tab sessions	Yes	No	No	No
Tab search	Yes	No	No	No
Duplicate cleanup	Yes	No	No	No
Whitelist wildcards	Yes	Yes	Yes	Limited
Tab group restore	Yes	No	No	No
Side panel	Yes	No	No	No
Dark mode	Yes	No	No	N/A
i18n languages	57	1	6	Varies
Export/backup	Yes	No	No	No
Size	~1.3 MB	~2 MB	~1.5 MB	Built-in
Tabs survive uninstall	Yes	No	No	Yes

Permissions

Drowzy requests only what it needs. Nothing is sent to external servers.

Permission	Purpose
tabs	List, suspend, and restore tabs
storage	Save settings, stats, and sessions locally
alarms	Periodic check for inactive tabs (every 60s)
contextMenus	Right-click menu: suspend, whitelist
scripting	Detect unsaved form data before suspending a tab
sidePanel	Display Drowzy in Chrome's side panel
optional_host_permissions	Requested only if you enable form protection or tab marking

Full details in the Privacy Policy.

Development

Drowzy is vanilla JavaScript -- no build tools, no dependencies, no node_modules. Clone and load:

git clone https://github.com/ml3dev/drowzy.git
cd drowzy

1. Open chrome://extensions in Chrome
2. Enable Developer mode (top right)
3. Click Load unpacked and select the drowzy folder
4. The extension icon appears in your toolbar -- you're running from source

Project structure

drowzy/
  background.js       Service worker (suspension logic, storage, alarms)
  popup.html/js/css    Popup UI (tab list, sessions, settings)
  sidepanel.html       Side panel (same UI, different layout)
  formcheck.js         Content script (form detection, suspend warnings)
  icons.js             SVG icon library
  onboarding.html/js   First-run welcome page
  changelog.html/js    What's new page
  privacy-policy.html  Privacy policy
  _locales/            57 language translations
  icons/               Extension icons (16-512px)

Contributing

Contributions are welcome. See CONTRIBUTING.md for guidelines.

Changelog

See CHANGELOG.md for the full version history.

License

MIT -- use it, fork it, learn from it.

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_{Built by ml3dev}