Firefox: Tamper Data 11.0 1

Once "Start Tamper" is selected, the extension pauses every outgoing request and prompts the user to "Tamper," "Submit," or "Abort".

If you are looking for :

The modern versions often require you to open a separate window before navigating, and the workflow is slightly more complex than the seamless overlay the legacy version provided. tamper data 11.0 1 firefox