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 match or …

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.

Jan 8, 2026 · 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 on a …

Jun 18, 2022 · Each section in this quick reference lists a particular category of characters, operators, and constructs that you can use to define regular expressions. We've also provided this information …

Dec 22, 2025 · A regular expression (regex) is a sequence of characters that defines a search pattern. It is mainly used for pattern matching in strings, such as finding, replacing, or validating text. Regex is …

Regular expressions or commonly called as Regex or Regexp is technically a string (a combination of alphabets, numbers and special characters) of text which helps in extracting information from text by …

Jan 9, 2026 · 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.

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

Aug 23, 2025 · Regex (short for regular expression or regexp) is a compact language for describing text patterns. If you’ve ever needed to find, validate, or transform strings at scale, regex is the fastest way …