Regex Builder & Explainer

Build, test, and explain regular expressions. Generates regex patterns from natural language descriptions, explains complex existing patterns step by step, and handles edge cases across JavaScript, Python, and Go flavors.

This skill translates between human intent and regex patterns. Describe what you want to match in plain English, and it generates the correct regex with explanation. Paste a complex regex, and it breaks it down step by step. Handles flavor differences between JavaScript, Python, Go, and PCRE.

When to use

Use when you need to write a regex for validation, parsing, or extraction; when you inherit a complex regex you don't understand; or when debugging regex that doesn't match what you expect.

Examples

Build from description

Create a regex from a natural language description

Write a regex that matches US phone numbers in any format — (555) 123-4567, 555-123-4567, 5551234567, +1 555 123 4567

Explain complex regex

Break down an incomprehensible regex pattern

Explain what this regex does step by step: ^(?=.*[A-Z])(?=.*[a-z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$