Add the requested inputs
Use the labelled fields in the workspace above. If example values are provided, try them first or replace them with your own.
Developer tools · Free online tool
Regex tester
Test a JavaScript regular expression, flags and replacement against sample text.
3 guest runs per rolling 24 hours10 with a free accountPrivate inputsMobile-friendly
Regex tester workspace
Runs locally in your browser
Uses the JavaScript regular expression engine. Syntax may differ from PCRE, Python or other regex flavours.
Result
Matches—
Match details
Use it with confidence
How to use the regex tester.
Calculate and review
Use the main action when needed. The browser RegExp engine applies the entered pattern and flags while output is rendered as safe text.
Try a worked example
Use named or numbered groups, inspect match indexes and preview a replacement before changing code.
Check the assumptions
Pathological expressions can be slow and JavaScript regex syntax differs from PCRE, Python and other engines.
Helpful answers
Regex tester FAQs.
Is the regex tester free?
Yes. Guests receive 3 runs per rolling 24 hours, verified free accounts receive 10, and Premium subscribers receive unlimited normal use.
Does UtilHub upload or save my inputs?
No. This tool runs in your browser and UtilHub does not receive or store the values you enter. Your browser or device may still retain normal local history or form data.
How does this regex tester work?
The browser RegExp engine applies the entered pattern and flags while output is rendered as safe text.
What should I check before using the result?
Pathological expressions can be slow and JavaScript regex syntax differs from PCRE, Python and other engines.