HTTP Header Manager

HTTP Header Manager lets you modify the headers your browser sends, without leaving the page you're working on. Create rules for the headers you need, then toggle them on and off as you work. Changes apply immediately — there's no save button and no page reload. WHAT YOU CAN DO • Add or replace a header — for example, force Accept: application/json so an API returns JSON instead of XML • Remove a header entirely • Keep multiple rules and switch individual ones on or off • Type any header name; common ones autocomplete, nonstandard ones are fine DETAILS • Rules are stored locally in your browser and never leave your machine • No account, no analytics, no data collection of any kind • Light, dark and system themes • Works in incognito windows once enabled in extension settings Only request headers are modified; response headers are not affected.