<!--
  Title: Awesome Regex
  Description: A curated list of amazingly awesome regex resources.
  Author: aloisdg
  -->

# Awesome Regex

[![Awesome](https://awesome.re/badge.svg)](https://awesome.re)
[![Main workflow](https://github.com/aloisdg/awesome-regex/workflows/Main%20workflow/badge.svg)](https://github.com/aloisdg/awesome-regex/actions)

## Introduction

A curated collection of awesome Regex libraries, tools, frameworks and software. The goal is to build a categorized community-driven collection of very well-known resources.

Inspired by [awesome-dotnet](https://github.com/quozd/awesome-dotnet), [awesome-ruby](https://github.com/markets/awesome-ruby), [awesome-awesomeness](https://github.com/bayandin/awesome-awesomeness) and the whole `awesome-*` trend on GitHub. Thank you [Reddit](http://www.reddit.com/r/regex), [Hacker News](https://news.ycombinator.com/item?id=9581225) and [Stack Overflow](http://stackoverflow.com/tags/regex/info) for the help.

Sharing, suggestions and contributions are always welcome! Please take a look at the [contribution guidelines and quality standard](https://github.com/aloisdg/awesome-regex/blob/master/CONTRIBUTING.md) first. Thanks to all contributors, you're awesome and wouldn't be possible without you!

## Contents

- [Documentation](#documentation)
- [Prototyping and Testing](#prototyping-and-testing)
- [Generators](#generators)
- [Security](#security)
- [Learning](#learning)
- [Libraries](#libraries)
- [Collections](#collections)
- [Explanation](#explanation)
- [Exercises](#exercises)
- [Articles](#articles)
- [Books](#books)
- [Benchmarks](#benchmarks)
- [Cheat Sheets](#cheat-sheets)

## Documentation

- [Regular Expression Language - Quick Reference](https://msdn.microsoft.com/en-us/library/az24scfc(v=vs.110).aspx) - MSDN documentation about Regex.
- [Regular Expressions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions) - MDN chapter about JavaScript regular expressions.
- [Perl Regular Expression Syntax](http://www.boost.org/doc/libs/1_43_0/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html) - Boost documentation.
- [Perl 6](https://docs.perl6.org/language/regexes) - Regexes in Perl 6.
- [PCRE](http://pcre.org/pcre.txt) - Concatenated PCRE man pages.
- [ECMAScript 6](http://2ality.com/2015/07/regexp-es6.html) - New Regexes in ECMAScript 6.
- [regex header in C++](http://www.cplusplus.com/reference/regex/) - `<regex>` in C++
- [class Pattern in Java](https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html) - Java 7 docs.
- [class Regex in Scala](http://www.scala-lang.org/api/2.12.1/scala/util/matching/Regex.html) - Scala Regex.
- [Python re module](https://pymotw.com/3/re/) - Regular Expressions Python module tutorial.
- [Regular Expressions in Perl](http://perl-begin.org/topics/regular-expressions/) - Introduction and Reference Links.

## Prototyping and Testing

- [Debuggex](https://www.debuggex.com/) - Online visual Regex tester.
- [ExtendsClass](https://extendsclass.com/regex-tester.html) - Online visual Regex tester.
- [Nodexr](https://www.nodexr.net) - Online node-based Regex editor.
- [Regexr](http://regexr.com/) - Website for interactive Regex prototyping with syntax highlighting (by @gskinner).
- [Regex101](https://regex101.com/) - Online Regex tester, debugger with highlighting.
- [Rubular](http://rubular.com/) - Ruby-based regular expression editor and tester.
- [Rex V](http://www.rexv.org/) - AJAX Regular EXpression eValuator.
- [RegViz](http://regviz.org/) - Tool for debugging JavaScript regular expressions in a visual way.
- [Regulex](https://jex.im/regulex) - JavaScript Regular Expression Visualizer.
- [PyRegex](http://www.pyregex.com/) - Online Regex tester to check validity of Regex in the Python language Regex subset.
- [pythex](http://pythex.org/) - Quick way to test your Python regular expressions.
- [Regexper](http://regexper.com/) - Regex visualizer for JavaScript using railroad diagrams.
- [HiFi Regex Tester](http://www.gethifi.com/tools/regex) - Live JavaScript Regular Expression Tester.
- [Regex Hero](http://regexhero.net/tester/) - .NET online Regex tester.
- [Regex Storm](http://regexstorm.net/tester) - .NET Regex tester with highlighting and detailed results output.
- [RegEx to Strings](https://www.wimpyprogrammer.com/regex-to-strings/) - JavaScript library and online tool to generate strings that a regular expression would match.
- [RegexPal](http://www.regexpal.com) - JavaScript + PCRE online tester.
- [RegexTester](http://www.regextester.com) - Regular Expression Tester with highlighting for Javascript and PCRE.
- [Free Formatter](http://www.freeformatter.com/regex-tester.html) - Free online Regex tester.
- [Regex Tester - Golang](https://regex-golang.appspot.com/assets/html/index.html) - A secure regular expression tester. built using Go
- [PHP Live Regex](https://www.phpliveregex.com) - PHP specific regular expression tester with live evaluation and code generation for all PHP's regex functions.

## Generators

- [Txt2Re](https://www.txt2re.com/index_php3.html) - Generate Regular expressions based on a string
- [Regex Generator++](http://regex.inginf.units.it) - Automatic Generation of Text Extraction Patterns from Examples
- [regexgen](https://github.com/devongovett/regexgen) - Generates regular expressions that match a set of strings.
- [RegexGenerator](https://github.com/MaLeLabTs/RegexGenerator) - A tool for generating regular expressions for text extraction (by @MaLeLabTs)
- [Gamon's numberic range generator](http://gamon.webfactional.com/regexnumericrangegenerator/) - Regex Numeric Range Generator, when you need to match an integer range.
- [rgxg](https://rgxg.github.io) - Command line tool to generate Regex
- [Strings to RegEx](https://www.wimpyprogrammer.com/strings-to-regex/) - JavaScript library and online tool to generate a regular expression that matches strings.
- [Regex Guide](https://regex.guide/playground) - Plain Text to Regex Generator.
- [grex](https://github.com/pemistahl/grex) - A command-line tool and library for generating regular expressions from user-provided test cases.
- [AutoRegex](https://www.autoregex.xyz/home) - English <-> Regex from an AI.

## Security

- [SafeRegex](https://github.com/jkutner/saferegex) - A command-line tool for testing regular expressions for [ReDoS](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS) vulnerabilities.

## Learning

- [Wikipedia][d1] - Entry on regular expressions.
- [Learn Regex The Hard Way][d2] - In-progress book that quickly teaches you regular expressions.
- [Regular Expression Matching Can Be Simple And Fast][d3] - Basic concept of how Regex parsing works.
- [PDF] [A Tao Of Regular Expressions][d4] - What are Regular Expressions.
- [Regular-Expressions.info][d5] - Informative website for learning regular expressions.
- [RexEgg][d6] - A regular expressions tutorial that goes deep into advanced features.
- [Try Regex][d7] - Try Regex is an interactive regular expressions tutorial.
- [Udemy][d8] - A Basic Introduction To Using Regular Expressions In Programming.
- [Codecademy][d9] - How to use of regular expression.
- [Regex golf][d10] - Regex golf with Peter Norvig.
- [Python Regular Expressions][d11] - A good introduction to Python Regular Expressions from Google.
- [/Reg(exp){2}lained/: Demystifying Regular Expressions][d12] - Fluent 2012 talk reviewing and visualizing basic and intermediate Regular Expressions.
- [Regular Expressions - Everything you should know][d13] - PDF Series.
- [The Java Tutorials][d14]
- [Regex Syntax Summary][d15]
- [How Regexes work][d16]
- [Learn Regular Expressions for Beginners][d17]
- [Java Regex Tutorial][d18]
- [Javascript.info - Regular expressions][d19] - Regular expressions section in The Modern JavaScript Tutorial
- [Useful Regexes][d20]
- [Teach Yourself Regular Expressions][d21]
- [Interactive Regex Tutorial][d22] - Learn Regex step by step, from zero to advanced.

[d1]: http://en.wikipedia.org/wiki/Regular_expression
[d2]: http://regex.learncodethehardway.org/book/
[d3]: http://swtch.com/~rsc/regexp/regexp1.html
[d4]: http://linuxreviews.org/beginner/tao_of_regular_expressions/tao_of_regular_expressions.en.print.pdf
[d5]: http://www.regular-expressions.info/
[d6]: http://www.rexegg.com/
[d7]: http://tryregex.com/
[d8]: https://www.udemy.com/learning-regular-expressions/
[d9]: http://www.codecademy.com/courses/javascript-intermediate-en-NJ7Lr/0/1
[d10]: https://www.oreilly.com/learning/regex-golf-with-peter-norvig
[d11]: https://developers.google.com/edu/python/regular-expressions
[d12]: https://www.youtube.com/watch?v=EkluES9Rvak
[d13]: http://neverfear.org/blog/view/Regex_tutorial_for_people_who_should_know_Regex__but_do_not___Part_1
[d14]: https://docs.oracle.com/javase/tutorial/essential/regex/resources.html
[d15]: http://www.greenend.org.uk/rjk/2002/06/regexp.html
[d16]: http://perl.plover.com/Regex/
[d17]: https://hackernoon.com/javascript-learn-regular-expressions-for-beginners-bb6107015d91
[d18]: http://www.vogella.com/tutorials/JavaRegularExpressions/article.html
[d19]: https://javascript.info/regular-expressions
[d20]: https://atrilsolutions.zendesk.com/hc/en-us/articles/205539861-Useful-regular-expressions
[d21]: http://rads.stackoverflow.com/amzn/click/0672325667
[d22]: https://regexlearn.com/

## Libraries

- [Tre](https://laurikari.net/tre/) - Free and portable approximate Regex matching library.
- [Go-Restructure](https://github.com/alexflint/go-restructure) - Match regular expressions into struct fields in Go (by @alexflint). [js](https://github.com/benjamingr/js-restructure) [C#](https://gist.github.com/benjamingr/4de21494b3e76088e5f7)
- [js-regex](https://github.com/wyantb/js-regex) - Chainable API for construting Regexes.
- [VerbalExpressions](https://github.com/VerbalExpressions) - VerbalExpressions is a cross-language library that helps to construct difficult regular expressions.
- [Super Expressive](https://github.com/francisrstokes/super-expressive) - Super Expressive is a JavaScript library that allows you to build regular expressions in natural language.
- [XRegExp](http://xregexp.com) - JavaScript Regex library.
- [RE2](https://github.com/google/re2) - RE2 is a fast, safe, thread-friendly alternative to backtracking regular expression engines like those used in PCRE, Perl, and Python. It is a C++ library.
- [Hyperscan](https://github.com/01org/hyperscan) - High-performance multiple Regex matching library.

## Collections

- [RegexLib](http://regexlib.com/) - Regular Expression Library (5000+ indexed expressions).
- [Regexhub](https://projects.lukehaas.me/regexhub/) - Useful Regex Patterns.
- [RGXP.RU](https://rgxp.ru/) - Regular Expression Patterns (+testing)

## Explanation

- [RegexTranslator](https://www.regextranslator.com/) - A web app to decode Regex into plain English. You can edit it and translate back.
- [Explain.pl](http://rick.measham.id.au/paste/explain.pl) - Explain Regular Expressions.

## Exercises

- [HackerRank Regex Challenges](https://www.hackerrank.com/domains/regex/re-introduction) - Regex challenges with varying levels of difficulty.
- [Redoku](http://padolsey.github.io/redoku/) - Little Regex Sudoku/Crossword thing (by @padolsey).
- [Regex Tuesday - Challenges](https://github.com/callumacrae/regex-tuesday) - Challenge list about Regex.
- [Regex Crossword](http://regexcrossword.com) - A crossword puzzle game using regular expressions.
- [RegexOne](http://regexone.com) - Learn regular expressions with simple, interactive examples.
- [Regex Exercises](https://regex.sketchengine.co.uk/) - Regexp exercises.
- [Regular Expression Crossword Puzzle](http://gregable.com/2015/12/regular-expression-crossword-puzzle.html) - A crossword puzzle with a neat web interface.

## Articles

- [5 Techniques to Improve Regex Performance](https://www.loggly.com/blog/five-invaluable-techniques-to-improve-regex-performance/) - Craft your own powerful, yet efficient regex.
- [The Bad, the Better, and the Best](https://www.loggly.com/blog/regexes-the-bad-better-best/) - How a few characters can make a difference in performance.
- [The Greatest Regex Trick Ever](http://www.rexegg.com/regex-best-trick.html) - So you're doubtful at the mention of a "best Regex trick"?
- [Treat regular expressions as code, not magic](http://alexwlchan.net/2016/04/regexes-are-code/) - If you don’t write them carefully, you can end up with an unmaintainable monstrosity.
- [Demystifying The Regular Expression That Checks If A Number Is Prime](https://iluxonchik.github.io/regular-expression-check-if-number-is-prime/) - How a regular expression can check if a number is prime.
- [Regex Tree: a regular expressions processor](https://medium.com/@DmitrySoshnikov/regexp-tree-a-regular-expressions-parser-with-a-simple-ast-format-bcd4d5580df6)
- [The thirty minute regex tutorial](https://www.codeproject.com/Articles/9099/The-Minute-Regex-Tutorial) - Regular Expressions in 30 Minutes.
- [Regular Expression Matching Can Be Simple And Fast](https://swtch.com/~rsc/regexp/regexp1.html)
- [Regular Expressions in a post ES6 World](https://ponyfoo.com/articles/regular-expressions-post-es6)
- [Regular expression (regex) performance: The fundamental guide](https://medium.com/@lennartkoopmann/regular-expression-regex-performance-the-fundamental-guide-3d39e6af33af)
- [The New ‘Absent Operator’ in Ruby’s Regular Expressions](https://medium.com/rubyinside/the-new-absent-operator-in-ruby-s-regular-expressions-7c3ef6cd0b99)
- [Optimizing regexes in Java](http://www.javaworld.com/article/2077757/core-java/optimizing-regular-expressions-in-java.html)
- [Use Regex to Test Password Strength in JavaScript](https://dzone.com/articles/use-regex-test-password)
- [Java 101](http://www.javaworld.com/article/3188545/learn-java/java-101-regular-expressions-in-java-part-1.html) - Regular Expressions in Java.
- [Most Crazy Regexes](https://stackoverflow.com/questions/800813/what-is-the-most-difficult-challenging-regular-expression-you-have-ever-written) - Stack Overflow
- [Regex Humor](http://www.rexegg.com/regex-humor.html) - Regex jokes and cartoons.
- [The true power of regular expressions](https://nikic.github.io/2012/06/15/The-true-power-of-regular-expressions.html)
- [On code, early neural networks, and once discredited AI pioneers](https://whyisthisinteresting.substack.com/p/the-regular-expression-edition) - A short history of regexes

## Books

- [Patterns, Automata, and Regular Expressions](http://infolab.stanford.edu/~ullman/focs/ch10.pdf) - Al Aho and Jeff Ullman (1992) (*chapter 10 of [Foundations of Computer Science](http://infolab.stanford.edu/~ullman/focs.html)*)
- [Beginning Regular Expressions](http://shop.oreilly.com/product/9780764574894.do) - Andrew Watt (2005)
- [Mastering Regular Expressions](http://shop.oreilly.com/product/9780596528126.do) - Jeffrey E.F. Friedl (2006)
- [Regular Expression Pocket Reference](http://shop.oreilly.com/product/9780596514273.do) - Tony Stubblebine (2007)
- [Introducing Regular Expressions](http://shop.oreilly.com/product/0636920012337.do) - Michael Fitzgerald (2012)
- [Regular Expressions Cookbook](http://shop.oreilly.com/product/0636920023630.do) - Jan Goyvaerts & Steven Levithan (2012)
- [Mastering Python Regular Expressions](http://shop.oreilly.com/product/9781783283156.do) - Felix Lopez & Victor Romero (2014)
- [JavaScript Regular Expressions](http://shop.oreilly.com/product/9781783282258.do) - Loiane Groner & Gabriel Manricks (2015)
- [Regex - the complete tutorial](https://www.princeton.edu/~mlovett/reference/Regular-Expressions.pdf)
- [Python re(gex)?](https://github.com/learnbyexample/py_regular_expressions) - Sundeep Agarwal (2020)

## Benchmarks

- [Benchmark of Regex Libraries](http://lh3lh3.users.sourceforge.net/reb.shtml)
- [Java regular expression library benchmarks – 2015](https://www.javaadvent.com/2015/12/java-regular-expression-library-benchmarks-2015.html)
- [Languages Regex Benchmark](https://github.com/mariomka/regex-benchmark) - It's just a simple Regex benchmark of different programming languages.
- [Performance comparison of regular expression engines](http://sljit.sourceforge.net/regex_perf.html)
- [Regex Performance](https://github.com/rust-leipzig/regex-performance) - Performance comparison of regular expression engines.

## Cheat Sheets

- [Regular Expressions Cheat Sheet](https://www.cheatography.com/davechild/cheat-sheets/regular-expressions/)
- [Regex Cheat Sheet](http://www.rexegg.com/regex-quickstart.html)
- [MIT Cheat Sheet](http://web.mit.edu/hackl/www/lab/turkshop/slides/regex-cheatsheet.pdf)
- [Java Cheat Sheet](https://zeroturnaround.com/rebellabs/java-regular-expressions-cheat-sheet/)
- [JavaScript Cheat Sheet](https://www.debuggex.com/cheatsheet/regex/javascript)
- [RegexLearn Cheat Sheet](https://regexlearn.com/cheatsheet)

# Other awesome lists

Other amazingly awesome lists can be found at the [official awesome list](https://github.com/sindresorhus/awesome) and [here](https://github.com/jnv/lists).
