Free Regex Tester
Test and debug regular expressions (RegEx) online with real-time match highlighting, group matching, and error checking. 100% private.
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Common Patterns
Test String
What is RegEx (Regular Expression)?
A Regular Expression (commonly abbreviated as RegEx or RegExp) is a sequence of characters that forms a search pattern. It is used to perform search-and-replace actions, validate input forms (e.g. verifying email formats, phone numbers), and extract patterns from documents.
Using syntax rules, regex matches combinations of characters in strings across various programming languages like JavaScript, Python, PHP, and Java.
Common RegEx Cheat Sheet Patterns
| Pattern | Description |
|---|---|
| [a-z] | Any lowercase letter |
| \d | Any numeric digit (0-9) |
| ^ | Start of string / line |
| $ | End of string / line |
| + | Matches 1 or more occurrences |
| * | Matches 0 or more occurrences |