Open source · MIT licensed

Dark mode that actually works

Force dark mode on every website.

Chrome, Edge and Brave all ship a dark-mode toggle, but it silently fails on GitHub, Google Docs, Sheets and more. Nox fixes that: one click and any page goes dark, properly.

Add to browser, free Star on GitHub
  • Chrome
  • Edge
  • Brave
  • Arc
  • Vivaldi
  • Opera
  • 100% offline
  • No Ads, No Tracking
  • MIT licensed
A webpage shown in its default light theme before Nox
Before: blindingly light
The same webpage after enabling Nox dark mode
After: one click, dark
  • Open source Full source code on GitHub, MIT licensed. Anyone can read it, audit it, or self-host it.
  • Private by design No accounts, no tracking, no analytics. Your data never leaves your browser.
  • Lightning fast One GPU-composited CSS filter. You won't notice any impact on browser performance.
  • Secure & offline Runs 100% offline with only two permissions. Nothing to phish, nothing to phone home.

Your browser's dark mode gives up on the sites you use most.

Built-in dark mode relies on sites cooperating. The ones that don't (GitHub, Google Docs, Google Sheets, and countless others) stay bright no matter what you toggle. Nox applies a real dark theme itself, so it works everywhere the browser can't.

Fast, private, and it actually works.

  • 🌐 Works everywhere

    A real dark theme on any site, including the ones the browser's dark mode ignores.

  • ⚡ One-click toggle

    Turn dark mode on or off globally, straight from the toolbar.

  • 🚫 Per-site ignore

    Don't want dark on a specific site? Ignore it with one click; that domain stays light.

  • 🔄 Syncs across devices

    Your preferences follow you through your browser's built-in sync.

  • 🔒 Lightweight & private

    No telemetry, no network requests, no servers, no account, just a tiny CSS filter that runs fully offline.

  • 🧩 Minimal permissions

    Only activeTab and storage. Nothing more.

Install in 30 seconds

  1. 1

    Download & unzip

    Click Download the extension (.zip) below and unzip it.

  2. 2

    Load unpacked

    Open chrome://extensions (Edge: edge://extensions), turn on Developer mode, click Load unpacked, and pick the unzipped folder.

  3. 3

    Pin & enjoy

    Pin Nox 📌 to your toolbar, click the icon, and every page goes dark.

⬇ Download the extension (.zip) View on GitHub →

Private by design.

Nox makes no network requests, ships no telemetry, runs on no servers, and needs no account. Your settings never leave your browser. It's a Dark Reader alternative that works fully offline, and only asks for activeTab and storage permissions.

Read the full privacy policy →

Speaks your language

Nox already ships in 11 languages and follows your browser's language automatically. More are on the way, and you can help add yours.

  • English
  • Español
  • Français
  • Deutsch
  • Português (BR)
  • Русский
  • العربية
  • हिन्दी
  • বাংলা
  • 日本語
  • 简体中文

Frequently asked questions

Does Nox work on GitHub, Google Docs and Google Sheets?

Yes. Nox applies a real dark theme to any site, including the ones the browser's built-in dark mode ignores.

Is Nox private?

Completely. No network requests, no telemetry, no servers, no account. Your settings never leave your browser.

Why does Nox exist, and is it safe to use?

Most dark-mode extensions are closed source, and many quietly send your data to external servers. Nox was built to be the opposite: fully open source under the MIT license, running entirely inside your browser with no network access at all. Nothing about you or your browsing ever leaves your device.

Does it slow down my browser?

No. A single GPU-composited CSS filter, toggled by one class. No loops, observers or polling. Fully offline.

Which browsers are supported?

Any Chromium browser: Chrome, Edge, Brave, Arc, Vivaldi, Opera. Firefox is not yet supported.

How do I install it?

Download the repo, open chrome://extensions, enable Developer mode, click Load unpacked, and select the folder. About 30 seconds.

What languages does Nox support?

Nox ships in 11 languages — English, Spanish, French, German, Portuguese (Brazil), Russian, Arabic, Hindi, Bengali, Japanese, and Simplified Chinese — and follows your browser's language automatically. More are added by the community over time.

Nox is built in the open. Come help shape it.

Nox is a free, open-source community project. Whether you write code or just speak another language, there's a meaningful way to contribute.

💻 Improve Nox

Found a bug, or have a feature in mind? Open an issue or send a pull request. Small fixes and big ideas are equally welcome, and the codebase is small and friendly.

Read the contributor guide →

Browse open issues

🌍 Translate Nox

Nox already reaches users in 11 languages. If yours is missing or could read more naturally, add it. Translating is just editing one JSON file, no coding required.

How to translate →

Browse the _locales folder