ModHeader was removed from Chrome and Edge. Here is how to move your header profiles in 2 minutes

ModHeader, a popular Chrome and Edge extension for modifying HTTP request and response headers, was removed from both Google and Microsoft stores in July 2026. The extension, which was installed by over 1.6 million users, had a hidden data-collection module that could collect visited domains and upload them to a remote server. This feature, while dormant by default, raised security concerns as the collector could be activated later without user consent.

The removal of ModHeader was due to a discovered issue in version 7.0.18, which contained the data-collection module. The extension also displayed ads and opened advertising tabs after updates. Despite the extension being removed from the stores, it is still installed in browsers that had it.

To move your ModHeader profiles to a replacement, first export your profiles from ModHeader by selecting Export → Export JSON → Download JSON. Then, remove ModHeader from your browser's extension list. Import the exported JSON file into a replacement extension, such as PureHeaders. Check the replacement extension for five important features: site access, its own network requests, remote configuration, unrelated bundled code, and where your values are stored.

After importing the profiles into PureHeaders, you can check that your headers are applied by opening the website you work on and clicking the PureHeaders icon. The top of the popup shows which rules were applied and how many rules are active. If a rule does not work, it may be because the site was not added or access was not granted. PureHeaders offers free features such as request and response headers, Fix CORS, URL filters, a 2-profile system, and an auto-off timer.