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Regular expression tester

Test JavaScript regular expressions in a timed Web Worker.

ReviewedGeneral utility
Saves this tool's name on this device only (up to 20). No form values.
Only visible result text is included. Form fields are not read. Review sensitive values before sharing.

Processed locally. Review generated code before deployment.

Enter values, then process to see the result.

How to use it

  1. Paste or enter input within the displayed limit for regular expression tester.
  2. Test JavaScript regular expressions in a timed Web Worker.
  3. Validate the output against the documented format and limitations before production use.

Important limitation

Limited to 150 ms and 200 matches; server-side ReDoS still needs separate testing.

The interactive form is fully localized in English.

Reviewed 2026-09-16; next review 2027-03-16.

Core calculations, cited sources and main examples have been reviewed within the stated scope.

Sources

ECMAScript — RegExp ObjectsEcma International · opens in a new tabUses JavaScript RegExp syntax in a worker with a timeout.Source checked 2026-09-16
Recorded updates

Review history

Site changelog

Dates describe the review scope recorded below. A page update does not mean every source was checked again.

  1. Last recorded source/method review

    Core calculations, cited sources and main examples have been reviewed within the stated scope.

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