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Available · Free

Regex Tester

Test a JavaScript regular expression against text in a disposable browser worker. See match positions, capture groups, and highlighted text.

Runs in a disposable worker with a 500 ms timeout. Limit: 300 pattern characters, 20,000 text characters and 300 matches. A complex expression may still consume CPU until termination. Empty matches appear in the list but cannot be highlighted.

Highlighted text

Enter a pattern and test text.

0 matches

    How to use it

    1. Enter a pattern, supported flags, and test text.
    2. Inspect highlighted matches, positions, and captured groups.
    3. Copy matches or try an example pattern.

    Example & limitations

    For example, use (?<year>\d{4})-(?<month>\d{2}) on 2026-10 to inspect named groups.

    300 pattern characters, 20,000 text characters, 300 matches, and a 500 ms worker timeout. A complex expression may still use CPU until it is terminated. Zero-length matches are listed, not highlighted.