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.
RegEX Cheat Sheet & Quick Reference
A quick reference for regular expressions (regex), including symbols, ranges, grouping, assertions and some sa
Regular expression "^ [a-zA-Z]" or " [^a-zA-Z]" - Stack Overflow
Jan 5, 2011 · So, "^ [a-zA-Z]" translates to "begins with character from a-z or A-Z", and " [^a-zA-Z]" translates to "is not either a-z or A-Z" Here's a quick reference: http://www.regular …
Regular expression syntax cheat sheet - JavaScript | MDN
Jul 8, 2025 · Non-word character class escape: Matches any character that is not a word character from the basic Latin alphabet. Equivalent to [^A-Za-z0-9_]. For example, /\W/ or /[^A-Za-z0-9_]/ matches …
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 real-time as you type. Roll over a match or …
RegEx for matching "A-Z, a-z, 0-9, _" and "." - Stack Overflow
Nov 12, 2009 · I need a regex which will allow only A-Z, a-z, 0-9, the _ character, and dot (.) in the input. I tried: [A-Za-z0-9_.] But, it did not work. How can I fix it?
Difference between regex [A-z] and [a-zA-Z] - Stack Overflow
The character class [A-z] will match every character between those characters, which in ASCII includes some other characters such as ' [', '\' and ']'. An alternative to specifying both cases would be to set …
Regex Tutorial - How to write Regular Expressions?
Apr 12, 2024 · Here's how to write regular expressions: Start by understanding the special characters used in regex, such as ".", "*", "+", "?", and more. Choose a programming language or tool that …
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 results.
Regex Cheat Sheet - A Regular Expressions Guide - HackerNoon
Oct 2, 2024 · Matches a literal dot (.) separating the domain name from the top-level domain (TLD). [a-zA-Z]{2,} Matches the top-level domain (TLD) consisting of at least two letters (e.g., .com, .org). $ …