RegEx Visualizer & Explainer vs regex101

RegEx Visualizer & Explainer is a browser tool for testing and debugging regular expressions. As a pattern is entered, it highlights matches and shows match and capture-group details. The tool explains individual tokens and provides a step-by-step debugger. Test mode checks pattern matches, Replace mode previews substitutions, and Diff mode compares two patterns. Test cases, presets, a cheatsheet, and browser history are also included. Matching uses the browser’s JavaScript RegExp engine and supports its regex flags. Testing runs in the browser; the page says content stays on the user’s device unless they copy or download a file. The tool runs on the web without installation or an account, and the Free plan costs nothing. It does not provide a multi-language code export panel, so patterns should be retested for differences in a target language. ToolsViewer describes its collection as intended for developers, students, designers, and other professionals. Support requests can be sent by email, with replies targeted within a few business days.

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.