Header Kit - HTTP Header & Cookie Editor

Edit HTTP headers, cookies, query parameters, and redirects with profiles, domain rules, variables, import, and export.

Header Kit is an HTTP header modifier and request rule manager for developers and QA engineers. Add, edit, or remove request and response headers, cookies, query parameters, and redirects without changing application code. Create separate profiles for local development, staging, authentication debugging, CORS testing, cache control, and issue reproduction. Scope rules by domain, URL, resource type, tab, window, or tab group. Key features: • Modify request and response headers • Add cookies and query parameters • Redirect matching URLs • Reusable variables and ordered filters • Independent profiles with quick on/off control • Import and export profile JSON Rules use Chrome Manifest V3 declarativeNetRequest. Your configuration stays in local Chrome storage.