HeadMod – HTTP Header & Cookie Editor

Add, change, or remove HTTP request and response headers and cookies on sites you choose. Free, local, no tracking.

Modify HTTP request and response headers and cookies on the sites you choose — privately. No ads, no tracking, no accounts. HeadMod can't see your traffic, by design. Built for developers and QA who need to test APIs, staging environments, auth, and CORS without touching server code. COMMON USES - Send an Authorization / Bearer token to an API or staging site - Get around CORS while developing locally (Access-Control-Allow-Origin) - Change User-Agent, Accept-Language, or X-Forwarded-For - Remove Content-Security-Policy or X-Frame-Options for debugging - Turn on feature flags or debug modes that are controlled by headers - Attach test cookies without editing them by hand FEATURES - Request headers — add, change, or remove (leave the value empty to strip it) - Response headers — the same, for headers coming back - Cookies — attach to outgoing requests or to responses - Profiles — separate rule sets (local, staging, a specific client), switch in one click - URL filters — scope a profile to matching URLs, or apply everywhere - Toggle any rule, or turn everything off with one shortcut; the badge shows active rule count - Also: undo/redo, light and dark themes, keyboard shortcuts PRIVACY, FOR REAL HeadMod uses Chrome's declarativeNetRequest API: your rules are handed to Chrome, and the browser applies them. The extension never intercepts or reads your network traffic. It starts with access to no sites. You grant access to all sites or one site at a time, and you can revoke it whenever you want. Rules are stored locally and never leave your device. WHY IT'S FREE I built HeadMod for my own day-to-day debugging and I'm sharing it in case it helps you too. There's no paid tier and no catch. It's open source, so you can check for yourself. Feedback, bug reports, and feature ideas are welcome: https://github.com/Lomank123/head-modifier/issues Source: https://github.com/Lomank123/head-modifier Author: https://lomank.com · https://www.linkedin.com/in/lomank