Debuggex vs RegexStudio

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.

RegexStudio is a free, open-source web workbench for testing and debugging JavaScript and PCRE2 regular expressions. Native JavaScript and PCRE2 10.47 through WebAssembly are listed as execution engines. Live results show matches and capture groups, while a step-through debugger records execution details. Railroad diagrams can be edited, and views cover explanations, tests, replacements, code generation, and abstract syntax trees. Test cases can check match status, counts, text, ranges, captures, and replacement output. Learning materials include interactive tutorials, practice mode, challenges, a pattern library, and a quick reference. Tutorials cover fundamentals and practical patterns, while noting that syntax varies among regex languages. Generated snippets target JavaScript/TypeScript, Python, Java, Go, Rust, C# (.NET), PHP, Ruby, Swift, and Kotlin. The interface, tutorials, and challenges support English, Simplified Chinese, and Japanese. Share links encode expressions, flags, test text, and replacements. PCRE2 workers have a two-second budget; debugger recording allows 2,000 checkpoints and 50,000 capture slots.