ModHeader By GreatJIN от Byungsoo JIN

ModHeader By GreatJIN is a personal header modification tool for testing and debugging HTTP request behavior.

It lets users create local profiles and rules to set, append, or remove request headers for matching URLs. It includes diagnostics for checking which rules match a target URL and inspecting request
header behavior during development.

This add-on stores rules locally and does not transmit collected data to external services.