Regex Tester & Matcher
Paste your regex and test string. See matches, capture groups, and substitutions in real time. Supports JS/PCRE flags (g, i, m, s, u). Match positions with character offsets.
Open Regex Tester →Regex Visualizer
Turn any regex into a railroad diagram. See alternation branches, repetition loops, and capture groups rendered as a syntax tree. Finally understand what your regex actually does.
Visualize Regex →Regex Cheatsheet
Quick reference for common patterns: email, URL, IP address, phone numbers, dates, credit card numbers. Copy-paste patterns with explanations. JS/Python/Go flavor notes.
Browse Cheatsheet →Regex Replace Tool
Find and replace with capture group references ($1, $2...). Bulk replace across multiple lines. Preview changes before committing. The regex tester includes a built-in replace mode —try it there.
Open Regex Tester →