RegexBuddy - RegexBuddy is your perfect companion for working with regular expressions.
regular expressions 101 - Extensive regex tester and debugger with highlighting for PHP, PCRE, Python and JavaScript.
Regex Forge - An Ultimate Regex Editor for macOS
RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.
The Regulator - The Regulator is an advanced Regular expressions testing tool, featuring syntax highlighting and...
RegexPal - An online JavaScript regular expression tester.