URL Rerouter

A tiny Chrome (MV3) extension that redirects URLs with simple wildcard rules — and lets you check exactly what a rule does before you rely on it. No save-and-pray like the original Redirector.

What it does

• Wildcard redirect rules. Write a From pattern with * and a To target with $1, $2, … Example: https://github.com/* → https://dev.github.com/$1.
• Debug any URL. Paste a URL and see which rule fires and where it lands — or exactly why none does (no match / disabled / shadowed by a higher rule). This is the testing loop: you confirm a rule before trusting it instead of guessing.
• Priority by order. Drag rules to reorder them; the topmost matching rule wins.
• Per-rule scope. Under Advanced, choose whether a rule applies to top-level pages, iframes, or both.
• Import / Export. Back up or share your rules as JSON.
• On/off in one click. The toolbar popup is a global switch with a live count of active rules.
• Minimal + small. Pure static MV3 files — no backend, no build step, no framework. The packaged extension is ~50 KB.

What you debug is what ships

The Debug any URL panel and the installed redirect run the same compiler (src/compile.js). Each rule compiles to a declarativeNetRequest dynamic rule (regexFilter + regexSubstitution), and a conformance test proves the regex we emit matches URLs identically under real RE2 (the engine Chrome uses) and the JS RegExp the debugger uses — so the debugger's verdict is the production verdict.

Pattern syntax

• * in the From pattern matches any run of characters and is captured.
• Reference captures in the To target as $1, $2, … (up to $9). Use $$ for a literal $.
• The whole URL must match (patterns are anchored). Matching is case-sensitive.
• Example: https://reddit.com/* → https://old.reddit.com/$1.

Redirects compile to RE2 (Chrome's declarativeNetRequest engine), so there are no backreferences or lookarounds — but for URL→URL redirects that covers what Redirector is actually used for.

Install (load unpacked)

1. Download or clone this repo.
2. Open chrome://extensions → enable Developer mode → Load unpacked → pick this folder.
3. Open the extension's Options to manage rules; the toolbar popup is the global on/off.

Develop

npm install      # playwright (for gates) + re2-wasm (for conformance)
npm test         # unit tests + RE2 conformance (no browser needed)
npm run test:ui  # drives the real UI in chromium + refreshes docs/screenshots
npm run package  # build dist/reroute-v<version>.zip for the Chrome Web Store

Tests:

• test/compile.test.mjs — the wildcard compiler/matcher (escaping, captures, $n substitution, anchoring, priority resolution).
• test/conformance.test.mjs — the "what you debug is what ships" proof: the emitted regex matches URLs identically under real RE2 (re2-wasm) and the JS RegExp the debugger uses.
• test/ui.mjs — drives the actual editor and reverse debugger in chromium.
• test/browser.mjs — a live gate that loads the unpacked extension and asserts a real navigation is redirected end to end (desktop only; see the note below).

Note: Chrome 137+ ignores the old --load-extension switch, and under Playwright's Chrome-for-Testing a CDP-loaded extension loads but stays inert (no service worker, pages blocked, DNR rules don't fire), so npm run test:browser can't drive it everywhere. To verify a live redirect, use the Load unpacked steps above in regular Chrome.

Privacy

URL Rerouter is private by design. Your redirect rules and the on/off setting are stored locally on your device via chrome.storage.local and are never transmitted anywhere. Redirects are performed by Chrome's own declarativeNetRequest engine — the extension does not run code on the pages you visit. The <all_urls> host permission exists only so your redirect rules can match any site; it does not read page content or send any browsing data anywhere. No analytics, no tracking, no third parties.

Full details: PRIVACY.md.

License

MIT — see LICENSE.