JustilityRegex tester
Test JavaScript regular expressions in a time-limited worker.
Processed on your device. Your files are never uploaded by Justility.
How privacy worksHow it works
Enter or choose input, adjust the options, then process and copy or download.
Supported formats
Text, JSON or CSV as appropriate; UTF-8 file input.
Good to know
JavaScript syntax only. Evaluation stops after one second; maximum input is 1 MB.
Using regex tester
Enter or choose input, adjust the options, then process and copy or download.
JavaScript syntax only. Evaluation stops after one second; maximum input is 1 MB.
Common questions
Are my inputs uploaded?
Justility processes this tool’s inputs locally and does not send them to a processing server. Public application assets are downloaded separately.
Can I use this without an internet connection?
Yes, after you prepare the relevant tool group from Offline help and the browser retains their assets. Installation is optional. All processing dependencies are bundled locally.