Regex Tester
Write a regular expression and see every match highlighted as you type.
✓ Free forever✓ No sign-up✓ No watermark✓ Files never leave your device
How to use the Regex Tester
- Enter your regular expression and pick flags.
- Paste the text to test.
- Review the highlighted matches and groups.
The tester uses JavaScript regular expression syntax. Toggle flags like ignore case and multiline, and see each match with its position and capture groups. Very complex patterns on long text can be slow, which is a feature of the regex itself.
Why use Toolbox
Frequently asked questions
Which regex flavor does this use?
It uses JavaScript (ECMAScript) regular expressions, which are very close to those in many other languages but not identical to every one.
What do the flags g, i, m, s and u do?
g finds all matches, i ignores case, m makes ^ and $ match at each line, s lets the dot match newlines, and u turns on Unicode mode.
Is this tool really free?
Yes, always free with no sign-up, no watermark and no file limits set by us.
Are my files uploaded anywhere?
No. Everything happens inside your browser, so your files and text never leave your device.