Regex Tester & Builder

Test and debug your regular expressions in real-time. Everything runs locally in your browser, ensuring your patterns and test strings remain 100% private.

Compliance Safe • Files processed locally

Regular Expression

Global (g)

Case Insensitive (i)

Multiline (m)

Test String4 matches

Hello world! This is a Test string for Regex.

Cheat Sheet

Character Classes

.Any character except newline

\wWord character (a-z, A-Z, 0-9, _)

\dDigit (0-9)

\sWhitespace (space, tab, newline)

[abc]Any character in the set

[^abc]Any character NOT in the set

[a-z]Any character in the range

Quantifiers

*0 or more times

+1 or more times

?0 or 1 time (optional)

{3}Exactly 3 times

{3,}3 or more times

{3,5}Between 3 and 5 times

Anchors & Boundaries

^Start of string (or line)

$End of string (or line)

\bWord boundary

Why use a Local Regex Tester?

Writing regular expressions can be challenging. An interactive tester helps you visualize exactly what your pattern matches in a given text. Because this tool runs strictly on the client side, you can safely test regex patterns against sensitive data (like log files, PII, or proprietary code) without worrying about your data being sent to an external server.

Features

Real-time Highlighting: Instantly see matching groups as you type.
Flag Toggles: Easily switch between global, case-insensitive, and multiline matching.
Built-in Cheat Sheet: Quick reference for common regex tokens.