REGEX TESTER

Full-featured regex debugger with live match highlighting, capture group extraction, code generation for 6 languages, and URL-shareable patterns. Everything runs in your browser — no server, no data sent.

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PATTERN
/ /g
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TEST STRING
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REPLACE
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CODE SNIPPET
Enter a pattern to generate code snippet
LIVE PREVIEW · CLIENT-SIDE
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QUICK REFERENCE
Character Classes
. Any char (except newline)
\d Digit (0-9)
\D Non-digit
\w Word char (a-z, A-Z, 0-9, _)
\W Non-word char
\s Whitespace
[abc] Any of a, b, c
[^abc] Not a, b, c
[a-z] Range a to z
Quantifiers
* 0 or more (greedy)
+ 1 or more (greedy)
? 0 or 1 (optional)
*? 0 or more (lazy)
+? 1 or more (lazy)
{n} Exactly n
{n,} n or more
{n,m} Between n and m
Anchors
^ Start of string/line
$ End of string/line
\b Word boundary
\B Non-word boundary
\A Start of string
\Z End of string
Groups & Lookahead
(abc) Capture group
(?:abc) Non-capturing
(?<name>abc) Named group
(?=abc) Lookahead
(?!abc) Neg. lookahead
(?<=abc) Lookbehind
(?<!abc) Neg. lookbehind
a|b a or b
ABOUT REGEX TESTER

Regular expressions are powerful pattern-matching tools used daily by developers to validate input, parse log files, extract data from API responses, and transform text. This tester runs entirely in your browser using the JavaScript regex engine — no data ever leaves your machine.

Multi-language code generation: Switch between JavaScript, Python, Go, Java, Ruby, and PCRE to instantly get idiomatic code for your target language. The generated snippet includes your exact pattern, flags, and match logic — ready to paste into your project.

Common patterns library: Click PATTERNS to browse 18+ pre-built patterns for emails, URLs, dates, UUIDs, semver, JWTs, hex colors, and more. One click to apply and test immediately against your input.

URL sharing: Use SHARE URL to encode your entire session (pattern, flags, test string, replacement) into the URL fragment. Share patterns with teammates or save them as bookmarks.