Regex Tester
Write a regular expression and test it against your text — matches are highlighted live, and you can preview a find-and-replace.
Your files never leave your device — everything runs in your browser.
//g
How to Use
- 1Type or paste a regular expression pattern.
- 2Toggle flags (g, i, m, s, u) and paste your test text.
- 3Matches are highlighted live; add a replacement to preview find-and-replace.
Frequently Asked Questions
Is my text sent to a server?
No — matching happens entirely in your browser using JavaScript's built-in regular expression engine. Nothing is uploaded.
What do the flag letters mean?
g finds every match instead of stopping at the first, i ignores letter case, m makes ^ and $ match the start/end of each line, s lets . match line breaks too, and u enables full Unicode matching.