Test a regular expression
Live highlighting, groups, flags and replace preview.
Runs on your device — never uploaded
How to test a regular expression
- Enter a pattern
With flags such as g, i, m, s, u.
- Paste test text
Matches highlight as you type; groups are listed.
- Try a replacement
See the substituted output with $1-style references.
Frequently asked questions
Which regex flavour is this?
JavaScript (ECMAScript), which covers most syntax shared with PCRE, Python and Go.
Can I share a regex?
Yes. The pattern, flags and text are encoded in the URL fragment, which never reaches a server.
Is my text uploaded?
No.