Regex Cheat Sheet
Searchable regex syntax reference: character classes, quantifiers, groups, lookarounds and flags. Free and private: runs in your browser.
Type a word such as "lookahead" or "group" to filter the table.
Runs entirely in your browser. Nothing you paste is uploaded or stored.
Use cases
- Find a syntax error before the build or deploy fails.
- Check config files in code review.
- Learn the rules your linter enforces.
Frequently asked questions
What is the difference between greedy and lazy?
Greedy quantifiers (*, +) match as much as possible; lazy ones (*?, +?) match as little as possible. <.+> matches a whole line of tags, <.+?> matches one tag.
Is the Regex Cheat Sheet free?
Yes. It is free with no sign-up, and it runs entirely in your browser, so your input is never uploaded or stored.
What should I do with the issues it reports?
Fix high-severity items first; they usually break builds or deployments. Lower-severity items are style and best-practice suggestions.
Related tools
Checking one snippet is a start. Scan your whole repository for free with CodeInspector.