Regular Expression (Regex) Cheat Sheet

Regex (short for regular expression), is a string of text that allows you to create patterns that help match, locate, and manage text.

Jump to: Regex Tester Tool

What is Regex?

Regular expressions are notations for describing patterns of text and, in effect, make up a special-purpose language for pattern matching. Although there are myriad variants, all share the idea that most characters in a pattern match literal occurrences of themselves, but some metacharacters have special meaning, such as * to indicate some kind of repetition or […] to mean any one character from the set within the brackets.

Beautiful Code by Andy Oram, Greg Wilson

More simply, Regex (short for regular expression), is a string of text that allows you to create patterns that help match, locate, and manage text.

Below is a quick reference Javascript regex cheat sheet. If you need a more in depth refresher or a place to get started I recommend these resources on regex:

LanguageReference Materials
JavacriptRegular expressions – JavaScript | MDN (

JavaScript RegExp Reference (
T-SQL (MS SQL Server)Search Text with Regular Expressions – SQL Server
Management Studio (SSMS) | Microsoft Docs
PythonRegular Expression HOWTO — Python 3.9.6 documentation

Python RegEx (
C LanguagesRegular expressions in C – GeeksforGeeks

An example of using regular expressions in C (

Regex Class (System.Text.RegularExpressions) | Microsoft Docs (C#)
Pearl (PCRE)perlre – Perl regular expressions – Perldoc Browser
Powershellabout Regular Expressions – PowerShell | Microsoft Docs
JavaJava Regular Expressions (

Lesson: Regular Expressions (The Java™ Tutorials > Essential Java Classes) (
Linux (Bash)How to Use Regular Expressions (regexes) on Linux (

Using Grep + Regex (Regular Expressions) to Search Text in Linux | DigitalOcean

Advanced Bash regex with examples – Linux Tutorials – Learn Linux Configuration
Other Resources and Reference MaterialComparison of regular-expression engines – Wikipedia

An introduction to regular expressions – O’Reilly (
Regex Reference Materials

Quick Reference Cheat Sheet

Character classes
.any character except newline
\w\d\sword, digit, whitespace
\W\D\Snot word, digit, whitespace
[abc]any of a, b, or c
[^abc]not a, b, or c
[a-g]character between a & g
^abc$start / end of the string
\b\Bword, not-word boundary
Escaped characters
\.\*\\escaped special characters
\t\n\rtab, linefeed, carriage return
Groups & Lookaround
(abc)capture group
\1backreference to group #1
(?:abc)non-capturing group
(?=abc)positive lookahead
(?!abc)negative lookahead
Quantifiers & Alternation
a*a+a?0 or more, 1 or more, 0 or 1
a{5}a{2,}exactly five, two or more
a{1,3}between one & three
a+?a{2,}?match as few as possible
ab|cdmatch ab or cd
Regex Cheat Sheet

Regex Tester Tool

Disclaimer: For educational and demonstrative purposes only. Always test your regular expressions before applying anything to a production system. Results from the above tool are not guaranteed.

How To Use:

  1. Type a regular expression in the Regex input box. (Leading and ending slashes are added automatically)
  2. Type a sample string to match against in the other box.
  3. Check out the resulting matches.
  4. Tweak your regex expression until you get the expected results to test your knowledge.