Free online AI regex generator to find the perfect regex pattern from a curated library of 35+ common patterns for emails, URLs, phone numbers, dates, credit cards, UUIDs, and more.
Each pattern includes a description, flags, and example text so you can test it instantly. Optionally, bring your own OpenAI or Anthropic API key to generate custom regex patterns by describing what you want to match in plain English. The AI key is stored only in your browser localStorage and is never sent to our servers. The built-in pattern library works without any API key, making this tool fully useful out of the box. No signup required.
How to Use AI Regex Generator
1Browse the pattern library by category or search for a specific pattern
2Click any pattern to load it into the tester with example text
3Paste your own text in the test area to see matches highlighted
4Optionally, enter your API key and describe a custom pattern in plain English to generate one with AI
Frequently Asked Questions
No. The tool includes 35+ pre-built regex patterns for common use cases like emails, URLs, phone numbers, dates, and more. These work without any API key. The AI generation feature is an optional bonus for custom patterns.
Yes. Your API key is stored only in your browser's localStorage and is never sent to our servers. When you generate a pattern, the request goes directly from your browser to the AI provider. We never see or store your key.
Add your API key, then type what you want to match in everyday words, for example 'a US phone number with optional country code' or 'words that start with a capital letter'. The AI returns a regular expression you can test immediately in the built-in tester.
Yes. The tool includes a built-in tester where you can paste any text and see matches highlighted in real time. It shows match count, indices, and highlighted text for easy debugging.
The library covers emails, URLs, phone numbers, dates, times, IP addresses, hex colors, UUIDs, credit card numbers, postal codes, usernames, passwords, and more. Each comes with flags and example text so you can confirm it matches what you expect before using it.