Regex Tester
A free, browser-based converter. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Input
Pattern
Flags
Test text
Output
Enter a pattern.
Runs entirely in your browser. Your input is not uploaded or stored.
How to use this calculator
- Enter a regex pattern, flags and some test text.
- See every match, its position and any capture groups.
How it works
Runs your pattern with the JavaScript regex engine and lists all matches and groups. Invalid patterns show a clear error.
Worked example
\d+ on 'a12 b3'. Matches '12' and '3'.
Tips
- Runs entirely in your browser. Your input is not uploaded or stored.
Frequently asked questions
Which flavour?
JavaScript regular expressions (the same engine the browser uses).
Privacy?
Runs entirely in your browser. Your input is not uploaded or stored.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.