Regex Tester
Test regular expressions with live match highlighting, capture groups, and flag controls.
Frequently Asked Questions
What regex flavor does this use?
It uses JavaScript's built-in RegExp engine, which supports most common regex features including lookahead, lookbehind, named groups, and Unicode.
Can I use regex flags?
Yes — toggle global (g), case-insensitive (i), and multiline (m) flags using the checkboxes.
More free tools
Paste an error or stack trace and get a plain-English explanation, the likely cause, and how to fix it.
Explain This Regex (AI)Paste a regular expression and get a plain-English explanation, a token-by-token breakdown, and example matches.
JSON Formatter & ValidatorFormat, validate, and beautify JSON data instantly. Catch syntax errors with line numbers.
Base64 Encode / DecodeEncode text to Base64 or decode Base64 strings back to plain text. Supports UTF-8.
Tired of debugging in production?
Bugsly catches errors before your users do — with AI-powered explanations and instant fixes.
Get Started Free