An online regex tester and debugger with real-time matching and plain-English explanations.
regex101 lets you build, test, and debug regular expressions with live match highlighting and an auto-generated explanation of your pattern. It supports multiple flavors and can generate code snippets.
Basic usage is free and does not require an account.
Flavors include PCRE2, JavaScript, Python, Go, Java, .NET, and Rust.
Information and links are accurate as of the time of writing and may change. Always verify on the official site. This is an independent guide, not affiliated with the listed services.