A functional, web-based browser-in-a-browser clone built with vanilla HTML, CSS, and JavaScript.

This project mimics the look and feel of a modern Firefox browser entirely within your own web browser. It utilizes multiple public CORS proxies and a srcdoc iframe injection to bypass standard cross-origin restrictions, allowing you to browse the web inside it.

• Authentic Firefox Theme: Faithfully recreates the modern Firefox aesthetic with CSS variables managing layout, hover states, and spacing.
• Dark/Light Mode: Full theming support. Toggling the theme updates the browser chrome, menus, internal pages, and even dynamically inverts specific favicons (like GitHub) for visibility.
• Tabbed Browsing: Open, close, and switch between multiple tabs. Each tab maintains its own loading state, favicon, title, and independent Back/Forward navigation history.
• Custom Start Page (about:home): Features the Firefox logo, a Bing-powered omni-search box, and a grid of customizable shortcut tiles.
• Interactive Toolbar: * Working Back, Forward, Reload, and Home buttons.
  • URL bar with focus states, "secure" lock icon, and a loading spinner.
  • Toggleable Bookmarks bar underneath the main navigation.
  • A dropdown hamburger menu containing theme toggles and new tab options.
• Status Bar: A dedicated bottom bar showing "Loading..." or "Ready" states.

• CORS Bypassing via Proxy Racing: To load external sites inside iframes without X-Frame-Options blocking them, the script races three different public proxies (allorigins, corsproxy, codetabs). The first to return valid HTML content wins.
• srcdoc Injection & Base Tag Fixes: Instead of just setting an iframe's src, the browser fetches the raw HTML, intelligently injects a <base> tag (so relative links and assets load correctly), and renders it via srcdoc with proper sandboxing.
• Smart Omnibox (URL Normalizer): Type a domain (e.g., github.com), a full URL, or just a search query. The script automatically detects the format and either prepends https:// or routes the query to a Bing search.
• Graceful Error Handling: If all proxies time out or fail to fetch a site, the browser renders a custom, themed "Secure Connection Failed" internal page.

Since this is built with vanilla web technologies, there are no build steps, bundlers, or dependencies to install!

1. Download the repository:

2. Open it: Simply open index.html in your favorite modern web browser (Chrome, Edge, Firefox, Safari).

3. Start Browsing: Use the Start Page shortcuts or type a URL/search query into the URL bar at the top!

• index.html - The core structure of the browser UI (toolbars, menus, and iframe containers).
• style.css - All styling, including CSS variables for theming, layout logic, and animations.
• script.js - The brains of the operation: tab management, history tracking, URL normalization, proxy fetching, and UI updating.

• Proxy Reliability: Because this relies on free public CORS proxies, loading speeds are dependent on their uptime. Some highly secure sites (like Google or banking sites) may still fail to load due to strict proxy-blocking or complex single-page-app architectures.
• Iframe Sandboxing: For security, the injected iframes are sandboxed. While scripts and forms are allowed, certain complex pop-ups or top-level navigations might be restricted. --

This project is licensed under the GNU General Public License v2.0. Note: This is a clone and is not affiliated with Mozilla.