RegEx Tester vs regex101

RegEx Tester has no write-up on Specifiction yet; its figures are above.

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.