What it does
Debuggex combines visual and text modes for regex testing, with expected and actual match views and unit tests.
Enter a pattern and sample string, then compare highlighted expected matches with the actual result. Switch between visual and text modes to inspect the pattern, and mark whether the captures are right. Adding unit tests requires login. A share link or embedded image can preserve the expression for discussion. Free users cannot generate code snippets using expressions from the library. Pricing offers Free, Basic and Pro plans, with more saved tests and private expressions advertised in paid plans.
Strengths
- Visual and text pattern views
- Expected versus actual match inspection
Watch out for
- Adding unit tests requires login
Best for
- Understanding an unexpected regex match
Sources
- Debuggex: Online visual regex tester. JavaScript, Python, and PCRE. (Oct 26, 2026)
- Debuggex sharing and free library-snippet restriction (Oct 26, 2026)
- Debuggex Free and paid plan scope (Oct 26, 2026)