How can I convert html.slim to html.erb?

I believe, you're actually looking for Slim::ERBConverter itself.

• If you are on rails projects, check out slim-rails how to integrate to your project.

• If you're on CLI, you even could use slimrb to easily convert many html.slim files into html.erb files with a single command.

• If you prefer online converter like you refer, there are simple online tools to help you convert e.g Slim to HTML / ERB, which is basically utilized Slim::ERBConverter itself.

try the slimrb utility...

slimrb --erb html.slim