regex101 vs RegexPlanet

regex101 is an online workspace for building, testing and debugging regular expressions. Its editor supports PCRE2, JavaScript, Python, Golang, Java,.NET 10.0, Rust, POSIX ERE, POSIX BRE and legacy PCRE. Explanations show how parts of a pattern match according to the selected flavor, and a step-through debugger helps follow matching. Match results can be exported as JSON, JSON Lines, CSV or plain text. Developer options include HTTP APIs, an MCP server, editor links and a separately licensed parser package. The workspace API stores editor data but does not provide a remote matching endpoint. File loaders read text, bytes and supported documents locally in the browser; saving or sharing workspace input can send it to the workspace service. Free includes core tools, one test string and saved workspaces with an account. Pro costs €4.99 a month, billed yearly, and adds multiple test strings, substitution pipelines, advanced benchmarking, formatting and an ad-free workspace. Enterprise is a self-hosted option with documented deployment on Linux using Docker Compose, MySQL and Redis.

RegexPlanet is a free web service for testing regular expressions during development. It offers separate test pages for engines including Java, Python, Bun, Go, Deno, Erlang, Haskell, MySQL, .NET, Node.js, Perl, PHP, PostgreSQL, Ruby, Rust, Swift, Tcl, XRegExp, and the browser. The Java tester accepts a pattern, replacement, and multiple input strings, with a control for adding more inputs. Options include case-insensitive matching, multiline mode, and Unicode-aware case folding. The home page provides a field for share codes, and the site directs users to Regex Zone for sharing expressions and finding patterns. A status page reports engine status and says each engine runs separately. RegexPlanet warns that malformed expressions may run indefinitely and that some engines or hosts may face denial-of-service attacks. Its privacy policy describes collection of IP addresses, browser data, and form entries; raw logs are stored by Google CloudRun. The service is offered as-is and as-available.