ModHeader Extension: HTTP Header Editor

Modify HTTP headers on any website. ModHeader Extension is a fast, clean, ad-free Chrome extension for modifying headers: add a custom header, edit HTTP headers, or remove them, on both requests and responses. Organize them into profiles and target exactly the sites you want. The free and Pro versions run entirely in your browser, with no account and no telemetry. Looking for a Mod Header alternative? This mod header editor is a clean, lightweight ModHeader Chrome extension replacement, rebuilt to respect your privacy. Wondering how to add a header? Create a rule, type the name and the value, and it applies instantly. No reload, no account, no setup. ✨ WHAT YOU CAN DO (FREE) ✓ Test a URL to see which rules would apply, and why the others would not ✓ Add, edit or remove custom headers on requests AND responses (set, append or remove) ✓ Unlimited profiles, switch with a single click ✓ Apply everywhere, or filter by URL ✓ Turn individual rules, a whole profile, or the entire extension on or off in one tap ✓ Import your existing ModHeader backups ✓ Export and share your setup as JSON ✓ Light and dark theme ✓ 51 languages ✓ No ads, no tracking, no account 🛠️ WHAT YOU CAN FIX WITH IT • CORS errors while developing: add Access-Control-Allow-Origin and the other CORS headers to responses • APIs that need auth: send an Authorization header (Bearer token or HTTP basic authentication) on every request • Stale cache: force Cache-Control: no-cache while you test • Embedding your own pages: remove X-Frame-Options or Content-Security-Policy from responses • Switching environments: keep your mod headers in profiles and swap the whole set of HTTP headers in one click • Cookies: add, change or remove Cookie and Set-Cookie with the built-in cookie editor (Pro) • Local testing: redirect production URLs to localhost (Pro) ⭐ PRO (one payment) ✓ Block matching requests entirely, like ads or trackers ✓ Target rules by HTTP method and request type (GET, POST, XHR, images…) ✓ Exclude specific domains from any rule ✓ Share a profile as a compact code ✓ Redirect any request to another URL ✓ Cookie editor (Cookie and Set-Cookie) ✓ Per-tab profiles: different headers on different tabs ✓ Regex URL conditions ✓ Export a profile as a ready to run cURL command ☁️ CLOUD (optional) ✓ Sync your profiles across up to 5 devices ✓ Team profiles: share them and everyone gets every change ✓ Variables per environment: write {{token}} once, switch between dev, staging and production ✓ Version history: go back to any earlier version of a profile Cloud is a monthly subscription. Lifetime gets you Pro and Cloud with a single payment. 🔒 PRIVATE BY DESIGN Without Cloud, everything happens on your device: no data collected, no telemetry, no account. The extension only contacts our server to validate a Pro license, if you buy one. If you turn on Cloud, we keep your email address and the profiles you sync, stored encrypted, only to sync your devices and your team. Your header rules never apply to our own server. 💡 PERFECT FOR • Web developers testing APIs, auth tokens and CORS • QA engineers reproducing and debugging requests • Teams that share the same headers and tokens across environments • Anyone who needs to set a User-Agent, add an Authorization header, or fix caching