.htaccess Validator & RewriteRule Simulator

About

.htaccess Validator & RewriteRule Simulator is a focused developer tool for anyone who writes Apache configuration. It runs entirely in your browser - nothing leaves your machine - and helps you catch the broken-redirect, infinite-loop, and access-control bugs that usually only show up in production.

WHAT IT DOES

Linter (17 rule codes, HT001 through HT204)
• Unbalanced container tags (<IfModule>, <Files>, <Directory> …) that would prevent Apache from starting
• Invalid RewriteRule / RewriteCond flags
• Force-HTTPS rules without a %{HTTPS} off guard (the classic infinite-loop bug)
• [R] without [L], [P] without a mod_proxy guard
• Deprecated Apache 2.2 access control (Order, Allow, Deny)
• Options +Indexes that accidentally expose directory listings
• Repeated Header set for the same name without an intervening unset
• Missing HSTS on HTTPS redirects
• R=302 used where R=301 is probably intended

URL Simulator
Paste your rules in one pane and your candidate URLs in the other. Click "Check rules" to see for each URL:
• Which rule fires
• The final URL or path
• The HTTP status (200, 301, 302, 403, 410)
• Whether the result depends on server state that the browser cannot simulate

Stats tiles count Redirected / Rewritten / Blocked / Pass-no-op / Conditional results. Filter pills narrow the table. Export to CSV for sharing or diffing.

Per-row Trace
Click the ▸ icon on any row to expand a step-by-step trace: input URL → RewriteCond evaluation (✓ / ✗ / ?) → pattern + subject + captures → substitution → final URL → terminating flag. Each rule label links back to the line in the editor.

Honest about its limits
Apache reruns rules in a loop until none match; this simulator is single-pass. Filesystem checks (-f, -d, -l) and unknowable request variables (HTTP_REFERER, REMOTE_ADDR, etc.) are reported as "Conditional" instead of being silently assumed. The "Limitations & assumptions" disclosure on the simulator page lists exactly what is and isn't evaluated.

PRIVACY

This extension does not collect or transmit any data. It makes zero network requests of any kind. There are no analytics, no telemetry, no third-party SDKs, no remote code. Everything you paste stays in your browser's memory until you close the window.

The only permission requested is `storage`, reserved for future local preferences. There is no host_permissions, no activeTab, no scripting, no tabs permission. The install dialog confirms this.

Full privacy policy: https://www.ajayrajbanshi.com.np/privacy-and-policy-htaccess-validator-rewriterule-simulator/

WHO IT'S FOR

• Backend / full-stack developers writing Apache configs by hand
• Sysadmins reviewing third-party .htaccess files before deploying
• SEO and migration engineers verifying that redirect rules behave as intended
• Anyone who's ever debugged a production redirect chain by adding RewriteLog statements at 2 a.m.

Support: [email protected]