Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/.NET, Rust.

Menu RegExr is an online tool to learn, build, & test Regular Expressions (RegEx / RegExp). Supports JavaScript & PHP/PCRE RegEx. Results update in real-time as you type. Roll over a …

A regular expression (shortened as regex or regexp), [1] sometimes referred to as a rational expression, [2][3] is a sequence of characters that specifies a match pattern in text.

Dec 8, 2025 · This page provides an overall cheat sheet of all the capabilities of RegExp syntax by aggregating the content of the articles in the RegExp guide. If you need more information …

RexExp Flags / Modifiers Flags can be added to a regexp pattern to modify its behavior:

Oct 29, 2025 · A regular expression (regex or regexp for short) is a special text string for describing a search pattern. You can think of regular expressions as wildcards on steroids.

Regular Expression Library provides a searchable database of regular expressions. Users can add, edit, rate, and test regular expressions.

1 day ago · Regular Expression Syntax ¶ A regular expression (or RE) specifies a set of strings that matches it; the functions in this module let you check if a particular string matches a given …

Regular expressions is a powerful way of doing search and replace in strings. Unicode: flag "u" and class \p {...} Sets and ranges [...]

Nov 9, 2025 · The RegExp object is used for matching text with a pattern. For an introduction to regular expressions, read the Regular expressions chapter in the JavaScript guide.