AI Regex Generator & Explainer
Common patterns: instant (client-side). Custom: AI-powered.
Common Presets (instant, no AI)
Custom
Common patterns are resolved instantly from presets. Otherwise AI is used.
What this tool does
Generates a regular expression from a plain-English description, OR explains an existing regex token-by-token. Includes test cases, supports JavaScript / PCRE / Python / POSIX flavors, and pre-built presets (email, URL, phone, IPv4, ISO date, UUID, hex color, ZIP, semver, slug, credit card) that resolve instantly without an AI call.
Who it's for: Developers working with text processing, form validation, log parsing, or data extraction who don't want to hand-write regex.
When to use
- •Build a validation regex for a user input field.
- •Decode an unfamiliar regex from a legacy codebase.
- •Generate a log-parsing pattern for a one-off task.
- •Switch regex flavors when porting code between languages.
How it works
- 1For common patterns, click a preset - result is instant.
- 2For custom patterns, describe what you need in plain English.
- 3Or paste a regex to get a token breakdown and test cases.
- 4Copy the pattern and test cases into your code.
Tips
- •Always test with edge cases - empty string, max length, unicode.
- •POSIX regex lacks lookaheads; use PCRE or JavaScript if you need them.
- •For critical validation, verify with a dedicated library (e.g. libphonenumber for phone numbers).