How do you enter a tab character in the test string without losing focus of the text field?
When I start typing the regex, the cheatsheet gets pushed below the visible part of the page as the "explanation" section expands itself. It would be nice if the cheat sheet remained next to the regex field as I typed in the regex.
Hmm, you could perhaps minimize the fields you dont need while writing it? Use the [-] buttons
1. Enter the test string.
2. Look at the cheat sheet and type into the regex field.
3. Look at the matches and test field to see if it was correct.
4. If incorrect, look at the explanation.
5. Go back to (2)
So for me, the default layout didn't handle my step (2) very well. I'm not saying that's the workflow you should optimize the UX for, but it's what mine was.