Regular expressions are powerful but tricky. This tester lets you write a pattern and instantly see what it matches in your sample text, with matches highlighted.
It runs in your browser so your patterns and text stay private.
How to use the Regex Tester
- Enter your regex pattern and flags.
- Paste the text to test against.
- See matches highlighted live.
Test regular expressions against real text
A regex that looks right and a regex that works are different things. The tester runs your pattern against sample text live, highlighting every match and capture group as you type, which turns regex writing from guesswork into immediate feedback. Flags for global, case-insensitive and multiline matching are toggled with a click.
The patterns everyone needs
A practical starter set: \d+ matches digits, \w+ matches word characters, ^ and $ anchor the start and end of a line, and [^,]+ matches everything up to a comma. Email checking commonly uses a pattern like ^[^@\s]+@[^@\s]+\.[^@\s]+$, which catches obvious mistakes without pretending to validate every legal address. Test edge cases deliberately: empty strings, spaces, and the text that should not match matter as much as the text that should.
Common uses
- Building validation for forms and inputs
- Writing search and replace patterns for editors
- Extracting data like dates and IDs from logs
- Debugging why a pattern matches too much or too little
Frequently asked questions
Is the regex tester free?
Yes, free with no signup.
Is my text uploaded?
No. Testing runs locally in your browser.
Which flavour of regex is used?
It uses JavaScript regular expressions.
Does it show all matches?
Yes. All matches are highlighted and counted.