regex101: build, test, and debug regex
Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/.NET, Rust.
RegExr: Learn, Build, & Test RegEx
Menu RegExr is an online tool to learn, build, & test Regular Expressions (RegEx / RegExp). Supports JavaScript & PHP/PCRE RegEx. Results update in …
Regular expression - Wikipedia
The phrase regular expressions, or regexes, is often used to mean the specific, standard textual syntax for representing patterns for matching text, as …
Regex Tutorial - How to write Regular Expressions
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, …
Regex Cheat Sheet
If you are a complete beginner, you should get a firm grasp of basic regex syntax just by reading the examples in the tables. I tried to introduce features in …
Regular expression syntax cheat sheet - JavaScript | MDN
Mar 17, 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 …
SimpleRegex - Free Online Regex Tester & Pattern Generator
Test and generate regular expressions in real-time. Free online regex tool for developers with syntax highlighting, pre-built examples, and instant match …
Python RegEx - W3Schools
A RegEx, or Regular Expression, is a sequence of characters that forms a search pattern. RegEx can be used to check if a string contains the specified …
Regex Cheatsheet - Complete Regular Expression Reference Guide ...
Comprehensive regex cheatsheet with syntax reference, character classes, quantifiers, anchors, and common patterns. Quick reference guide for regular …
Regular expression HOWTO — Python 3.14.5 documentation
1 day ago · Regular expressions (called REs, or regexes, or regex patterns) are essentially a tiny, highly specialized programming language embedded …