Regex Generator & Explainer

Describe a pattern in plain English and get a working regex with a plain-language breakdown and test cases.

The Prompt — replace [BRACKETS] with your details

Act as a regular expressions expert. Create a regex for this requirement:

[DESCRIBE WHAT TO MATCH, e.g., "US phone numbers with optional country code and dashes or spaces"]

Where it will be used: [LANGUAGE/TOOL, e.g., JavaScript, Python, grep]

Deliver:
1. The regex pattern
2. A piece-by-piece explanation of what each part does
3. 5 test strings that SHOULD match and 5 that should NOT, with a one-word reason each
4. Common edge cases this pattern intentionally does or doesn't handle
5. If the requirement is better solved without regex, say so and explain why

How to use this prompt

Be specific about what should NOT match — that’s where most regexes break.
Always test against the provided non-matching examples in your own environment.

Works well with

ChatGPT

Claude

DeepSeek

Need a custom version of this prompt?

The free prompt generator builds a prompt tailored to your exact goal, framework, and target AI model — or paste this template into the optimizer to refine it.

→ Open the Prompt Generator → Prompt Optimizer

Related prompts

Code Review Assistant

Paste code and get a structured review covering bugs, readability, performance, and securi…

Debug Any Error Message

Paste an error message and the related code to get the likely root cause, a fix, and how t…

Unit Test Generator

Generate thorough unit tests for any function, covering happy paths, edge cases, and failu…

Code Documentation Writer

Generate clear docstrings, inline comments where needed, and a README-style usage section …