Why Regular Expressions Are Hard
A regex like \b[A-Z][a-z]+\b looks like line noise to most people — and even experienced developers routinely get them subtly wrong. The fix isn't memorising syntax; it's seeing what your pattern actually matches in real time.
What a Good Regex Tester Should Show You
Our Regex Tester provides all of this instantly, entirely in your browser — nothing is sent to a server.
Common Regex Patterns (Cheat Sheet)
| Pattern | Matches |
|---|---|
| \d+ | One or more digits |
| [A-Za-z]+ | One or more letters |
| \b\w+@\w+\.\w+\b | Simple email-like patterns |
| ^https?:// | URLs starting with http:// or https:// |
| \s+ | One or more whitespace characters |
Common Flags
Step-by-Step
Frequently Asked Questions
Does this tool support all regex features?
It uses your browser's native JavaScript regex engine — so anything valid in JavaScript works here.
Is my text uploaded anywhere?
No — all matching happens locally in your browser using the Web's built-in RegExp engine.
Why does my pattern match nothing?
Check for unescaped special characters (like ., *, (, )) that need a backslash, or try adding the i flag if your text has different casing than expected.
Related Tools
Once you've nailed your pattern, you might also like the Diff Checker for comparing text, or the UUID & Hash Generator for generating test data.