I would say that Regex Storm is the best since it’s made specifically for testing regular expressions in .NET (which is what UiPath is using).
What is Regex Storm?
Regex Storm helps you build and test regular expressions in .NET. There are a lot of online regex testers out there, but my goal was to make a good one specifically for .NET developers.
RegexStorm is the MOST compatible site with UiPath, but please note there are still some small differences between UiPath and RegexStorm.
For example:
In RegexStorm,
“^” = the start of the entire string
“$”= the end of an entire string
But in UiPath
“^” = the start of a single line.
“$”= the end of a single line.
The simplest of differences can make solving a pattern easier. Lots of forum users use Regex101.com simply because you can share your Regex Pattern - that’s it.
I regularly use both sites. With regex101.com to share with others or RegexStorm if its just me figuring out a pattern.
If you want to Learn Regex - feel free to check out my Regex MegaPost:
If in doubt - make a post (like you did) and you will get assistance from the community
@Steven_McKeering Regarding the difference with ^ and $, is it documented anywhere or have you found it out by trial and error?
According to Microsoft ^ should match the beginning of a string, unless the multiline option is specified, in which case it will match the start of each line.
Start of String or Line: ^
By default, the ^ anchor specifies that the following pattern must begin at the first character position of the string. If you use ^ with the RegexOptions.Multiline option (see Regular Expression Options), the match must occur at the beginning of each line.
@Steven_McKeering Thank you for your reply. Out of curiosity, I did a quick test with the Matches activity in UiPath Studio. It seems to be working according to Microsoft’s description so it doesn’t seem to be any difference in this regard with UiPath and RegEx Storm anymore.