This is a great idea! It didn't behave the way I expected with some URLs as input, though:
http://example1.org/path/index.html
http://www.example2.org/path/index.html
http://www.example3.org/
https://www.example4.org/a/b/c/d/e/f/g/hijklmnop
The pattern I gave was: example1.org, path/index.html
So I expected to get: example1.org, path/index.html
www.example2.org, path/index.html
www.example3.org,
www.example4.org, a/b/c/d/e/f/g/hijklmnop
Instead, I got: example1.org, path/index.html
wwwexample.2, org/path.index
wwwexample.3, org/.
wwwexample.4, org/a.b
A few feature requests: allow downloading the output as a text file; show a pseudo-code formula of how transformy interpreted the transformation, like "s/.+:\/\/(.+?)\/(.*)/\1, \2/"; and add support for common arbitrary transformations like "November"↔"NOV"↔"11", or "2"↔"2nd".