ThemeBench

Inject CSS and HTML into pages with reusable themes and snippets.

ThemeBench is the ultimate companion for web developers, designers, and power users who want to take full control over their browsing experience. Whether you’re debugging a live site, prototyping new styles, or simply want to customize your favorite web applications, ThemeBench provides a powerful, intuitive interface for persistent CSS and HTML injection. Key Features =========== Reusable Themes & Snippets: Organize your code into reusable snippets and combine them into themes. Domain-Specific Targeting: Automatically apply themes based on the website you're visiting. Group your themes by domain for easy management. Live Injection: See your changes in real-time as you type, with powerful code editors for CSS and HTML. Shared Snippet Library: Maintain a global library of common utilities (like custom fonts or reset styles) and use them across multiple themes. Mutual Exclusivity: Use Domain Groups to ensure only one theme is active at a time for specific sites—perfect for light/dark mode toggles or branding variations. Productivity-First UX: Features like double-click to rename, drag-and-drop import/export, and a custom tooltip system make managing your tweaks a breeze. Safe & Reliable: Built with modern extension standards (Manifest V3) and optimized for performance. Export and import your entire workspace or individual groups with ease. Why ThemeBench? Unlike simple "custom CSS" extensions, ThemeBench is a full-fledged development environment for your browser. It’s designed for those who need more than just one-off tweaks—it’s for anyone who wants a structured, professional way to manage web customizations. Get Started ========== Create a new Theme. Add CSS or HTML snippets. Set your target domain (or run everywhere). Watch your web experience transform!