Test and debug Regular Expressions in real-time with visual highlighting, pattern replacement, token cheat sheets, and 1-click code export.
Presets:
//g
Flags:
TEST STRING INPUT
MATCH RESULTS (0 FOUND)
No matches found.
What is a Regular Expression (Regex) Tester & Generator?
A Regular Expression (Regex) is a powerful search pattern string used by software developers for text pattern matching, string validation, search-and-replace, and data extraction. Our online Regex Tester & Matcher allows you to test patterns in real-time with live highlighting, evaluate flags, replace strings with capture groups, and generate ready-to-use code snippets for JavaScript, Python, PHP, and Java.
How to Test & Debug Regular Expressions
Enter Pattern & Flags: Type your regex pattern inside the top input bar (e.g. ^[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$) and toggle flags like g (global), i (case-insensitive), or m (multiline).
Input Test String: Paste sample target text into the input panel to see live matches, match indexes, and capture groups.
Replace & Export Code: Use the "Match & Replace" tab for string substitutions or open "Export Code" to generate native regex code for your programming language.
Key Features & Capabilities
Match & Replace Engine: Substitute matched patterns using capture group variables ($1, $2).
Multi-Language Code Generator: Export working code snippets for JavaScript, Python, PHP, and Java instantly.
Built-in Cheat Sheet: Quick reference drawer for common tokens like \d, \w, \s, ^, and $.
Ready-Made Presets: Preloaded regex patterns for Email validation, URLs, Phone Numbers, IPv4 Addresses, and HEX Color Codes.
Frequently Asked Questions (FAQ)
What does the global (g) flag do?
The g flag instructs the regex engine to search for all occurrences in the text instead of stopping after the first match.
How do capture groups ($1, $2) work in replacement?
Parentheses (...) create capture groups. In replacement strings, $1 refers to the content matched by the first parenthesized group, $2 to the second, and so on.