Prompt Library
Coding

Regex Generator + Explainer

Get the regex, the explanation, and the failure cases.

The Prompt
Write a regex that matches: [describe pattern]
Sample strings it MUST match: [examples]
Sample strings it must REJECT: [examples]

Return: the regex, a token-by-token explanation, and 3 tricky inputs where a naive version would fail.
Fill in before using
[pattern][examples]

How to use it

  • → Paste the prompt into your model of choice — it works with any frontier model.
  • → Replace every bracketed placeholder with your specifics. Concrete inputs beat vague ones every time.
  • → If the model asks a clarifying question, answer it — these prompts are designed to invite that.
  • → Iterate on the output, not the prompt. The structure is already tuned.
regexvalidation

More Coding prompts