Extension comparison

Chrome header & request tools, compared

If you're evaluating header or request-modification extensions for API development, here's how three common options differ in scope and data handling. ModHeader was flagged as malware and removed from the Edge Add-ons store in July 2026 (see the dedicated page for sources). Requestly is a full-featured, open-source HTTP interceptor with a much broader feature set than a header-only tool. Header Relay is the narrowest of the three, built for one job.

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At a glance

	ModHeader	Requestly	Header Relay
Primary scope	Header add/modify/remove with environment profiles	Full HTTP interceptor: headers, API mocking, redirects, response overrides, script injection	Header capture and relay only
Open source	No	Yes — public GitHub repository	No — verify via Chrome DevTools' network tab and the published privacy policy instead
Known security incidents (public record)	Flagged as malware by Google; removed from the Microsoft Edge Add-ons store, July 2026	None reported at time of writing	None reported at time of writing
Captured/attached values visible in the UI	Not reviewed on this page	Not reviewed on this page	Yes — shown in plain text in the popup and management screen

Read the full comparison

ModHeader alternative

Full detail on the July 2026 malware flag and what Header Relay does differently.

Requestly alternative

Full detail on the scope trade-off if you only need header relay.

Header Relay is not affiliated with ModHeader, Requestly, or their developers. Claims about ModHeader reflect third-party security research published in July 2026; claims about Requestly reflect its public documentation and GitHub repository. See the linked pages for sources.