Online nástroje pro psaní, testování a ladění regulárních výrazů.

- **[regex101](https://regex101.com/)** — the most feature-rich tester; supports PCRE, JavaScript, Python, Go and others; explains each token and highlights matches with detailed breakdown
- **[RegExr](https://regexr.com/)** — visual regex tester with community patterns and cheatsheet
- **[RegexPal](https://www.regexpal.com/)** — simple JavaScript regex tester
- **[PHP Live Regex](https://www.phpliveregex.com/)** — PHP-specific tester with live output using `preg_match`, `preg_match_all`, `preg_replace` and `preg_split`
- **[ExtendsClass Regex Tester](https://extendsclass.com/regex-tester.html)** — multi-language tester (PHP, Python, JavaScript, Java, Ruby, Go)