RegEx Visualizer & Explainer vs RegExr

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.

RegExr is a free web tool for learning, building, and testing regular expressions. It supports JavaScript and PHP/PCRE expressions, with results that change as you type. Hovering over a match or expression reveals details, and the Explain tool describes an expression in plain English. Tests mode lets users assemble examples that an expression should match or reject. Replace and List produce custom outputs, while Details shows capture groups. Learning resources include a cheatsheet, reference, help pages, and examples. Users can search and rate Community Patterns, then save and share expressions. Signing in keeps favorites and patterns in My Patterns. A saved expression gets a public link, and a Community-shared copy cannot be edited or deleted. The listed RegExr plan costs nothing. The project README credits Grant Skinner and gskinner.com as creators and identifies this version as GPL v3 licensed. It directs issue and feature requests to GitHub and regular-expression questions to Stack Overflow.