devcrate / Dev Utilities / Regex Tester
Dev Utilities
Test regex against real text.
Write a pattern, toggle flags, and see every match highlighted live against your own test string.
runs entirely in your browser — nothing is uploaded
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How to use the regex tester
- Type a regular expression pattern (without slashes).
- Toggle flags — g (global), i (case-insensitive), m (multiline), s (dotall).
- Paste your test text and click Test to see matches highlighted inline.
Common regex syntax reference
Syntax
Matches
.
Any character except newline
\d \w \s
Digit, word character, whitespace (uppercase = negated)
* + ?
Zero or more, one or more, zero or one
{n,m}
Between n and m repetitions
^ $
Start of string/line, end of string/line
[abc] [^abc]
Character set, negated character set
(...) (?:...)
Capturing group, non-capturing group
a|b
Match a or b
\b
Word boundary
Frequently asked questions about the Regex Tester
Is my data uploaded anywhere when I use the Regex Tester?
No. The Regex Tester runs entirely in your browser using JavaScript — nothing you type, paste, or select is sent to any server. You can confirm this yourself by opening your browser's network tab while using it.
Is the Regex Tester really free, and do I need an account?
Yes — the Regex Tester is completely free, with no account, sign-up, or usage limit.
Does it work on mobile and in any browser?
The Regex Tester works in any modern browser — Chrome, Firefox, Safari, or Edge — on desktop or mobile, since it's built with standard HTML, CSS, and JavaScript with no special requirements.