Regex playground and online tester
7 matches · flags: gi · 4 characters
Test lines 4 of 5 lines match · 7 matches
- ✓1 match
apple code developer1 match - ✓2 matches
REGEX is amazing and powerful2 matches - ✓1 match
contact support@regexhunter.com or find info1 match - ✓3 matches
04-03-2026 dates matched cleanly3 matches - 0 matches
hello world!0 matches
A JavaScript regex tester in your browser
Type a pattern and every match lights up as you go, on your own test lines or on a block of text. The playground runs JavaScript's RegExp, the same engine as your browser, Node.js and the daily game. Matches lists each match with its capture groups, Anatomy breaks the pattern into its parts, and Share puts the pattern, flags and lines into one link.
Start with the regex cheat sheet or a practice pack.
Questions
Which regex flavour does this tester use?
JavaScript (ECMAScript), as in every browser and in Node.js. Lookbehind (?<=…) and named groups (?<name>…) work. JavaScript has no possessive quantifiers a++ or atomic groups (?>…), so patterns from PCRE, Java or .NET that use them won't run here.
How do I test a regex with flags?
Use the buttons at the end of the pattern box: g finds every match instead of only the first, i ignores case, and m lets ^ and $ match at the start and end of each line.
Can I share a regex?
Yes. Share copies a link with your pattern, flags and test lines, and whoever opens it sees the same matches. Nothing is saved on our server: everything is in the link.
Why does my regex stop with “Too slow”?
Some patterns, like (a+)+$, take exponentially longer on text they almost match. This is called catastrophic backtracking. The playground matches in the background and stops after a quarter of a second, so your tab never freezes. Rewrite the pattern so each character can be matched only one way.