Developer tools
Regex tester
Test a regular expression live against your text, with matches highlighted and groups shown.
Anything you type or paste stays in your browser — it is not uploaded to Tools99.
Workspace: 1. Add files2. Ready3. Working4. Done — download
How this workspace works
- Type your regular expression and your test text.
- Read the highlighted matches and the groups shown.
- Adjust the pattern until it matches exactly what you intend.
Your text never left this browser, so there is no server copy to delete. Copy it again, start over, or continue with a related tool below.
How to use Regex tester
- Type your regular expression and your test text.
- Read the highlighted matches and the groups shown.
- Adjust the pattern until it matches exactly what you intend.
A good use for this
Testing a pattern for validation, searching, or extraction before putting it into code.
Limits
A pattern that matches your test text may still fail on real input — test edge cases (empty strings, unusual characters) before trusting it in production.