Regex Tester
Test JavaScript regular expressions and inspect matches and capture groups.
Test text up to 100 KiB, patterns up to 2,000 characters and at most 1,000 matches. Runs in a cancellable worker with a time limit. Match positions use JavaScript UTF-16 indices. All processing stays on this device.
Result
Your result will appear here after processing.
How do I use this tool?
Enter a pattern without surrounding slashes, choose JavaScript flags, and paste test text. Results include match positions and capture groups.
What does it support?
Test text up to 100 KiB, patterns up to 2,000 characters and at most 1,000 matches. Runs in a cancellable worker with a time limit. Match positions use JavaScript UTF-16 indices.
Does my input leave my device?
No. Processing runs locally in your browser. Input and results are kept only on this page and are cleared when you leave, reload or clear the tool. Copy and download happen only when you choose those actions.