Headerwise: Modify HTTP Headers

Modify request and response headers per profile. Import your ModHeader profiles. Runs locally, sends nothing anywhere.

Headerwise changes HTTP request and response headers in Chrome and Edge. Set, append or remove headers, group them in profiles, and turn them on only where you need them. It runs entirely in your browser. There is no account and no analytics, and the extension cannot send anything anywhere: its manifest forbids network requests, so the browser itself blocks them. Header changes are applied by the browser through declarativeNetRequest, so Headerwise never reads the pages you visit. WHAT YOU CAN DO • Request and response headers: set, append or remove, per profile. • Profiles: as many as you like, several on at once. Duplicate them, drag to reorder (the leftmost wins a shared header), switch with a keyboard shortcut. • Filters: only on or never on URL patterns and regular expressions, only for requests made by some sites, only for some request types (page, fetch/XHR, scripts…) or methods, or only in one tab. • On this tab: open the popup to see which profile changed how many requests on the current page, and why another one didn't. • Paste from DevTools: copy a request as cURL, fetch or PowerShell, paste it, and pick the headers you want. • Redirects: replace part of the address, for example send api.example.com requests to your staging server. ModHeader's URL replacements import as redirects, and its cookie rules as Cookie and Set-Cookie headers. • Presets: CORS, remove Content-Security-Policy, allow a site in an iframe, Bearer token, no cache, iPhone or Googlebot User-Agent, and more. • Variables: {{uuid}}, {{timestamp}}, {{date}} and others, filled in on every edit and refreshed every minute. • Secrets stay hidden: tokens and cookies show as dots until you click the eye, handy when you share your screen. • On for a while: switch a profile on for 15 minutes up to 8 hours and it switches itself off, so a token or a production header isn't left on by accident. • Export and import profiles as JSON. Secret values are left out unless you ask for them. Exports from Requestly and Simple Modify Headers import too. • Automated tests: a separate build for Selenium, Playwright and Puppeteer sets headers from your test, and runs tests written for ModHeader with only the extension swapped. Download and setup: https://protemir.github.io/headerwise/automation.html • Light and dark theme. COMING FROM MODHEADER? ModHeader was removed from the Chrome and Edge stores in July 2026. If your browser turned it off, its Export button is gone too, but your profiles are still on your disk. Headerwise reads ModHeader's folder right in the page (nothing is uploaded) and brings the profiles over, filters included. Exported ModHeader JSON files work too. WHY NOT JUST DEVTOOLS? DevTools is great for looking at headers. It can't add request headers like Authorization to every request, and its overrides only work while DevTools is open in that one tab. Headerwise works in every tab, all the time, until you pause it. Free, with no limits. Everything listed here is free and will stay free. Open source (MIT): https://github.com/Protemir/headerwise