freeregextester.app is a free online regex tester that lets you write, test, and debug regular expressions with real-time match highlighting. Type your regex pattern, paste your test string, and see matches highlighted instantly. freeregextester.app shows full match details including capture groups, positions, and match values. All processing runs locally in your browser with zero tracking — your patterns and test data never leave your device. freeregextester.app supports JavaScript regex syntax with global, case-insensitive, multiline, dotAll, and Unicode flags.
Type your regular expression between the slashes at the top, toggle the flags you need (global, case-insensitive, etc.), and paste or type your test string in the left panel. Matches are highlighted in real time and full details appear in the right panel, including capture group values and character positions. Click any pattern in the Quick Reference to insert it into your regex.
freeregextester.app is completely free with no sign-up required. All regex matching happens locally in your browser using JavaScript's native RegExp engine. There are no ads, no tracking, and no usage limits.
freeregextester.app uses the JavaScript RegExp engine, which supports character classes, quantifiers, alternation, capture and non-capture groups, named groups, lookaheads, lookbehinds, Unicode property escapes, and the full set of standard regex flags (g, i, m, s, u).
Yes. freeregextester.app is fully responsive and works on any device with a modern browser. On mobile, the panels stack vertically so you can see both the test string and match details comfortably.
Absolutely. freeregextester.app processes everything locally using JavaScript. There is zero server communication, no cookies, no analytics, and no tracking. Your regex patterns and test data are only stored in your browser's localStorage for convenience, and never uploaded anywhere.
Yes. freeregextester.app is 100% free with no sign-up, no ads, and no usage limits. All regex processing happens in your browser.
freeregextester.app uses JavaScript's built-in RegExp engine, which supports standard regex syntax including lookaheads, lookbehinds, named groups, and Unicode properties.
Your current pattern and test string are saved locally in your browser's localStorage so they persist between sessions. Nothing is sent to any server.
Yes. You can toggle global (g), case-insensitive (i), multiline (m), dotAll (s), and unicode (u) flags with one click.
Yes. freeregextester.app is a progressive web app that works offline after your first visit. No internet connection needed.
Absolutely. freeregextester.app has zero tracking, no cookies, and no analytics. Everything runs locally in your browser. Your patterns and test data never leave your device.