Regex From Examples

Give match and non-match examples, get a regex plus a plain-English breakdown and extra test strings.

Intermediate1 min readJul 27, 2026

#regex #parsing #utilities

Customize

Fill these in and the prompt below updates as you type. Anything you leave blank stays as a placeholder.

Flavor

Should match

Should not match

Your prompt

3 placeholders left

Write a regex for {{flavor}} that matches the SHOULD-MATCH strings and rejects the SHOULD-NOT strings.

Should match:
{{should_match}}

Should NOT match:
{{should_not_match}}

Return: the regex, a plain-English explanation of each part, and 3 extra test strings you would add to be sure it is correct.

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