Regex Tester
Free online regex tester. Test JavaScript regular expressions against text with live highlighting, capture groups and flags. Debug your regex instantly and privately.
Online regex tester
Write a regular expression and test it against sample text with live highlighting and capture-group details. Tweak the pattern and flags and see matches update instantly — perfect for building and debugging regex for JavaScript, validation, search-and-replace and data extraction.
Frequently asked questions
Which regex flavor does this use?
It uses JavaScript (ECMAScript) regular expressions — the same engine browsers and Node.js use. Most patterns are compatible with other languages too.
What do the flags mean?
g = global (all matches), i = case-insensitive, m = multiline (^ and $ match line breaks), s = dotall (. matches newlines), u = unicode, y = sticky.
Is my text private?
Yes. Matching runs entirely in your browser — your pattern and test text are never sent anywhere.