Is there a Firefox extension that add a rename feature (for example a textbox) to Firefox's
Download Dialog ?
If you right click on a link and select
Another option is the DownThemAll extension. This gives you much more control over your downloads including renaming.
You may not need an extension if all you are trying to do is just give a name to a file as you start to download it. In Firefox:
Answer was taken from https://support.mozilla.com/en-US/questions/749403#answer-31655.