Header Hero

About

Header Hero adds, overrides and removes HTTP request and response headers, so you can test an API, unblock CORS, or flip a feature flag without touching your code or standing up a proxy

It opens on the site you're already looking at. Click the icon and you see that site's headers, with one switch to turn them off. You never type a hostname - the extension already knows it

1) runs entirely on your machine (no network calls at all ).
2) asks for nothing at install (host access is optional, requested at first rule).
3) tells you when Chrome won't cooperate (the DNR limits it surfaces instead of failing silently).