simple-modify-headers

good

This now breaks YouTube.

It works as described. Simple and clear. Open source. What's missing is a more functional popup with the ability to switch headers.

Don't adding a header on redirect requests.

Convenient and functional extension. My only wish: Enable the ability to have multiple data (rules) profiles, at least so that the old data is not erased during import.

works, wish it had a regex/js way of writing values based on URL or other variables

very useful

Tried the others, this is the best header rewrite tool there is. Very impressed.