regex101
Regex101 is a comprehensive web-based utility designed for developers to write, test, and debug regular expressions efficiently. As you type your regex pattern, the tool automatically generates a plain-language explanation of its structure and highlights match results in real time against provided test strings. It supports multiple regex flavors including PCRE, Python, JavaScript, and Go. Additionally, it features a built-in quick reference cheat sheet for tokens, anchors, and quantifiers, facilitating rapid development without leaving the interface.
Checked on Sep 30, 2026.
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