Regex quiz

Fun & miscellaneous //en/tools/regex-quiz

Loading tool

The tool is loaded only when you open it.

All processing for this tool happens in your browser. Your input is not sent to a server.

About this tool

Each challenge provides a target, hint, and samples. Enter JavaScript regex source and flags to test required matches and required rejections separately.

Common uses

Practice anchors, character sets, quantifiers, and format validation.
Check a regex idea quickly without sending samples to a server.

How to use it

1.Choose a challenge and read its target and hint.
2.Enter regex source and optional flags, then submit.
3.Review passed status and failed samples before moving to the next challenge.

Limits and notes

Tests use the browser's JavaScript RegExp rules; the built-in date challenge checks only the YYYY-MM-DD shape, not whether the date exists.

Frequently asked questions

Which regex flags can I use?

You can enter flags supported by JavaScript RegExp, such as i, m, and g; unsupported combinations show a syntax error.

Is quiz progress saved?

No. Progress remains on the current page and resets after a refresh.