This is the only autofill I found that was able to selectively save and load all page fields with a click. Highly underrated.

It avoids many problems I found with other autofills: It allows you to select based on URL or domain so does not try to force itself globally. It only saves or loads selected fields. It fills verbatim and does not try to make guesses about data from a library or use dummy data.

This is the only extension that works on my setup (Linux Ubuntu + Firefox).
It is a working fork of "Web Developer Form Filler by Eric Busch".