Intelligent Auto Engine
Scans page luminance, DOM structure, and media density to apply the optimal dark strategy. If a site natively supports dark mode (like YouTube or GitHub), it leaves it untouched.
Manifest V3 • 100% Offline & Private
Dark Mode Extension for Chrome
Transform any website, document, or local PDF into an eye-friendly, customizable dark theme. Powered by intelligent engine selection, layout preservation, and zero data tracking.
Zero data collected
No white flashes
Built-in PDF reader
Open source MIT
Engineered for Quality, Speed, and Eye Comfort
Most dark mode extensions either bruteforce color inversion or inject thousands of slow CSS rules. ThemeSwitcher takes an algorithmic, performance-first approach.
Local PDF & Document Dark Reader
Say goodbye to blinding white PDF tabs. The built-in document viewer uses bundled PDF.js with saturation-aware canvas pixel conversion so diagrams and text stay readable offline.
CSS Override Engine
Recolors backgrounds, typography, forms, inputs, and borders using mathematical contrast palettes. Smart detection selectively inverts black logos on dark backgrounds.
Custom Background Palettes
Prefer deep pitch black (#000000) for OLED displays or a softer midnight slate (#0f1115) for evening reading? Choose any custom background hex color per domain right from the popup.
Zero White Flashes
Injected at document_start with CSS custom property bindings before the DOM renders.
Your eyes are never subjected to blinding flashes between page navigations.
100% Offline & Zero Tracking
No telemetry. No tracking pixels. No analytics beacons. No external servers. Your browsing history never leaves your device, and preferences sync only via your personal Google account.
How ThemeSwitcher Compares
An honest, factual breakdown of how ThemeSwitcher differs from native flags and standard inverters.
| Feature | ThemeSwitcher | Native Chrome Flags | Generic Color Inverters |
|---|---|---|---|
| Per-Site Preferences | ✓ Instant (per domain) | ✗ Global only | ✓ Supported |
| Native Dark Detection | ✓ Leaves dark sites intact | ✗ Inverts everything | ✗ Variable / Glitchy |
| Offline PDF Dark Viewer | ✓ Built-in PDF.js engine | ✗ No | ✗ Often broken |
| Custom Background Colors | ✓ Pitch black, slate, or custom | ✗ Fixed algorithm | ✗ Limited sliders |
| Page Reload Required | ✓ No (Instant Toggle) | ✗ Browser restart required | ✓ No |
| Zero Telemetry / Offline | ✓ 100% Local & Private | ✓ Local | ✗ Varies by publisher |
Frequently Asked Questions
Everything you need to know about ThemeSwitcher, privacy, and how it works.
A dark mode extension modifies webpage styling dynamically to replace harsh white backgrounds with soothing dark tones while keeping text readable and preserving pictures, diagrams, and video elements.
Simply add ThemeSwitcher from the Chrome Web Store. Once installed, click the extension icon in your browser toolbar on any website to toggle dark mode on or off. The extension will automatically remember your choice for that website.
Yes. The Auto Engine adapts to article sites, wikis, social networks, and web applications. If a site already features an active dark theme (such as YouTube in dark mode), ThemeSwitcher detects this and leaves the site’s native dark colors alone.
Yes, ThemeSwitcher is 100% free and open-source under the MIT license. It runs entirely on your device with zero telemetry, zero analytics tracking, and zero data transmitted to any external server.
When you open a PDF or click "Open PDF in dark viewer" in the popup, ThemeSwitcher opens the document in an offline, sandboxed reader powered by local PDF.js. It converts pixels using a saturation-aware algorithm that preserves colors in charts and illustrations while darkening white page backgrounds.