✦ New Tool

Regex Tester Pro

Test and debug regular expressions in real-time. View match counts and highlighted results with full flag support.

Tool

Pattern

Flags

Test Text

Ctrl+Enter to process

Match Results

Learn

Why Use a Regex Tester?

Regular expressions are powerful but tricky to get right. A regex tester gives you instant feedback on your patterns, showing exactly what matches and what doesn't — so you can iterate quickly and avoid bugs in your string processing logic.

Related Tools

JSON Formatter

Format, validate, and minify JSON data with syntax highlighting.

Diff Checker

Compare two texts and highlight differences line by line.

URL Encoder/Decoder

Encode and decode URLs, query strings, and special characters.

Frequently Asked Questions

What regex flavors are supported?

This tester uses JavaScript's built-in RegExp engine, supporting standard patterns including groups, lookaheads, character classes, quantifiers, and flags (g, i, m, s, u, y).

Is my regex or test data stored or uploaded?

No. All regex testing happens entirely in your browser. Your patterns and test data never leave your device.

How do I use flags?

Enter flags in the flags field: g (global - find all matches), i (case-insensitive), m (multiline - ^ and $ match line boundaries), s (dotall - . matches newlines), u (unicode), y (sticky).