Test regular expressions
Test regular expressions against a text and see matches in real time, protected against patterns that would hang the tab.
Processed on your device. Nothing is sent to any server.
Test regular expressions against a text and see matches highlighted in real time, protected against patterns that could hang the tab.
The pattern runs in a separate Web Worker with a time limit: if a pattern with excessive backtracking takes too long, it's stopped automatically instead of freezing the page.
Use cases
- Debugging a regular expression before using it in code.
- Extracting specific patterns from a text.
- Validating a data format (email, phone, zip code).
How it works
- 1
Type the pattern
Enter the regular expression, without the leading and trailing / slashes.
- 2
Add the test text
Matches are calculated automatically.
Frequently asked questions
- What happens if my pattern is very slow?
- Execution is automatically stopped after a time limit, protecting your browser from freezing due to catastrophic backtracking patterns.