Regex Toolkit
Build, test, visualize, and debug JavaScript regular expressions — five tools covering the whole regex workflow. All run entirely in your browser.
How these fit together
If you're not confident writing a pattern from scratch, Regex Builder lets you click character classes, quantifiers, and groups together instead. Once you have a pattern — built or hand-written — Regex Tester shows live match highlighting against real text, and Regex Visualizer breaks it down into a diagram of groups and alternatives when the pattern itself is hard to read at a glance. Before shipping anything performance-sensitive, Regex Debugger steps through the match attempt to catch catastrophic backtracking before it becomes a production incident. And Regex Cheat Sheet Generator builds a custom syntax reference you can export and keep next to you while you work.
Regex Builder
Build a JavaScript regular expression visually by clicking pattern pieces.
Regex Tester
Test JavaScript regular expressions with live match highlighting.
Regex Visualizer
Break a regular expression down into a visual diagram of groups, alternatives and quantifiers.
Regex Debugger
Step through a regex match attempt and catch catastrophic backtracking before it ships.
Regex Cheat Sheet Generator
Build a custom JavaScript regex syntax reference and export it as Markdown or plain text.