Regex Tester

Test a regular expression against your text with live highlighting, match counts and capture groups. Runs entirely in your browser.

📖 Read the guide: How to Test a Regular Expression →

global (g) ignore case (i) multiline (m) dotall (s)

Test string

Matches

How it works

Enter a pattern

Type your regular expression (no slashes needed) and set the flags.

Add test text

Paste the text you want to match against in the box below.

See live matches

Every match is highlighted as you type, with a running count.

Inspect groups

Capture groups for each match are listed so you can confirm what was captured.

Frequently Asked Questions

Which regex flavor is this?

JavaScript (ECMAScript) regular expressions — the same engine your browser and Node use.

What do the flags mean?

g = all matches, i = case-insensitive, m = ^/$ match line starts/ends, s = dot matches newlines.

Is my text or pattern uploaded?

No — matching runs in your browser, so nothing is sent to a server.

Test and debug regular expressions online for free with live match highlighting. Enter a JavaScript regex and flags (global, ignore-case, multiline, dotall), paste your test string, and instantly see every match highlighted along with the capture groups. It is perfect for building and verifying patterns for validation, search-and-replace and scraping. Everything runs in your browser, so your patterns and text never leave your device.