regex101 vs RegexStudio

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.

RegexStudio is a free, open-source web workbench for testing and debugging JavaScript and PCRE2 regular expressions. Native JavaScript and PCRE2 10.47 through WebAssembly are listed as execution engines. Live results show matches and capture groups, while a step-through debugger records execution details. Railroad diagrams can be edited, and views cover explanations, tests, replacements, code generation, and abstract syntax trees. Test cases can check match status, counts, text, ranges, captures, and replacement output. Learning materials include interactive tutorials, practice mode, challenges, a pattern library, and a quick reference. Tutorials cover fundamentals and practical patterns, while noting that syntax varies among regex languages. Generated snippets target JavaScript/TypeScript, Python, Java, Go, Rust, C# (.NET), PHP, Ruby, Swift, and Kotlin. The interface, tutorials, and challenges support English, Simplified Chinese, and Japanese. Share links encode expressions, flags, test text, and replacements. PCRE2 workers have a two-second budget; debugger recording allows 2,000 checkpoints and 50,000 capture slots.