Debuggex vs RegexRegex

Debuggex is an online visual regex tester for JavaScript, Python, and PCRE. It offers visual and text modes, a step-through debugger, and pattern explanations for examining expressions. Users can add unit tests to check matches and subgroups as a regex changes, and browse a repository of pre-built expressions that includes tests. The service generates code snippets, saves patterns, and creates links that reopen expressions; expressions can also be embedded in StackOverflow answers. The Free plan costs nothing and includes two saved unit tests per regex and ten public expressions. Basic costs $5 a month, while Pro costs $15 a month. Enterprise has no listed price and includes options such as private server deployment, denial-of-service prevention, flexible user counts, an OEM license, and on-site training. The free tier excludes snippets based on expressions from the library. The privacy policy says saved or shared expressions can be viewed by anyone with the link, and previous versions are stored after updates. Debuggex is available on the web.

RegexRegex is a free browser-based tool for building and testing regular expressions. Its checker runs JavaScript patterns in the browser and shows matches, captures, explanations, and errors, with previews for replacement text. A guided builder composes basic JavaScript patterns using controls for character types, quantities, groups, boundaries, and flags. It can test the pattern it creates, but does not cover every syntax feature or convert arbitrary patterns into an equivalent visual layout. Python, PHP, Java, .NET, and Perl engines can be used by explicitly pressing Run, which sends checks to an online execution service. Replacement previews recognize numbered and named captures such as $1 and $. The searchable reference covers 25 syntax and flag items. Users can save up to 50 test cases in the browser, each with input up to 20,000 characters. Share links include the selected pattern, engine, flags, and operation; test and replacement text are omitted unless users opt in. A cached JavaScript checker may work offline, while checks using other engines need the online service.