PlainHeaders – HTTP Header Editor

Add, change or remove HTTP request & response headers. Open source, no tracking, access only to sites you choose.

PlainHeaders is a small, honest HTTP header editor for developers — a drop-in replacement if you lost ModHeader. • Set, append or remove request and response headers (Authorization, CORS, CSP, User-Agent, X-Forwarded-For…) • One-click presets: CORS allow-all, remove CSP / X-Frame-Options, disable caching, mobile user agent • "This tab only": lock a profile to the current tab so other tabs stay untouched • Profiles you can switch in one click; pause everything instantly; badge shows active header count • Import your ModHeader export (JSON) or PlainHeaders backups; export anytime • Private by design: no analytics, no ads, no remote code. Host access is requested per site when you click "Enable on this site" — never all sites at install. Only network call: the license check for Pro (ExtensionPay). Pro ($7 one-time, via ExtensionPay/Stripe; arriving in the next update): run several profiles at once, URL filters per profile, URL redirects (e.g. swap a production script for localhost). The free tier has no header limit and never nags. Built with AI assistance; maintained by an independent developer. Support: via the CWS support tab.