Regex Tester

How It Works

Enter a regex pattern and test string — matches are highlighted in real-time as you type. Toggle flags to control matching behavior and view capture groups for each match.

Features

• Live Highlighting: Matches highlighted instantly as you type the pattern or test string
• Flag Toggles: Global (g), case insensitive (i), multiline (m), and dotall (s)
• Capture Groups: Named and numbered groups displayed for each match
• Match Count: Total matches shown with individual match details
• Error Feedback: Invalid patterns show the browser’s native error message

Common Patterns

Here are some useful regex patterns to get started:

• Email: [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
• URL: https?://[^\s/$.?#].[^\s]*
• Phone (US): \(?[0-9]{3}\)?[-.\s]?[0-9]{3}[-.\s]?[0-9]{4}
• Date (YYYY-MM-DD): \d{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])
• IPv4 Address: \b(?:\d{1,3}\.){3}\d{1,3}\b
• Hex Color: #(?:[0-9a-fA-F]{3}){1,2}\b

Regex Quick Reference

Pattern	Matches
.	Any character (except newline without s flag)
\d	Digit (0-9)
\w	Word character (letter, digit, underscore)
\s	Whitespace
^ / $	Start / end of string (or line with m flag)
* / + / ?	0+, 1+, 0 or 1
{n,m}	Between n and m occurrences
(...)	Capture group
(?:...)	Non-capturing group
(?=...)	Positive lookahead
[abc]	Character class