Two tools developers use constantly: a regex tester to debug patterns and a JSON compare to see differences between two documents. Both run best in the browser—paste pattern and sample, or paste two JSON documents, and get instant results.
A good regex tester highlights matches and groups and supports your engine’s flavor. A JSON compare tool shows line-by-line or character diff with highlights. Free online versions mean no install and quick access from any machine.
Use our Regex Tester and JSON Compare for debugging and comparison—free developer tools.