AI Regex Generator & Explainer
Generate a regex from plain English, or paste a regex to have it explained.
The AI Regex Generator works both ways. In Generate mode it turns a plain-English description into a working regular expression with an explanation. In Explain mode it takes a regex you paste and breaks it down token by token in plain English, with example matches — so you understand any pattern, not just copy it.
- ✓Generate mode: plain English → regex + explanation
- ✓Explain mode: paste a regex → token-by-token breakdown
- ✓Handles emails, phones, dates, passwords, URLs and more
- ✓Test the result in the Regex Tester
How to Generate a Regex with AI
Type what you want to match — for example "a US ZIP code" or "words between curly braces" — and click Generate. The assistant returns a single regular expression on the first line, followed by a short explanation of each component. Paste the result into the Regex Tester to try it against your own text and confirm it matches exactly what you expect.
Common Things Developers Generate
- ▸Input validation — Emails, phone numbers, URLs, postal/ZIP codes, strong passwords and credit-card formats for forms and APIs.
- ▸Log & text parsing — Extract IPs, timestamps, request paths, error codes or IDs from log lines and raw text.
- ▸Search & replace — Build patterns for find-and-replace in your editor, sed, or a codemod script.
- ▸Data extraction & scraping — Pull hashtags, mentions, prices, dates or query parameters out of unstructured strings.
- ▸Understanding a cryptic regex — Paste an inherited pattern into Explain mode to learn exactly what it matches before you change it.
- ▸Learning regex — See how a plain-English requirement maps to lookaheads, character classes, quantifiers and anchors.
Tips for Better Regex Results
Be specific about what should and shouldn't match, and give example strings — "match a US phone like (555) 123-4567 but not 5551234" produces a far better pattern than "a phone number." If you need a particular flavor (JavaScript, Python re, PCRE, Go RE2), say so, because syntax like lookbehind differs between engines. Always paste the result into the Regex Tester and try it against real and edge-case inputs before shipping — a pattern that validates untrusted user data must be tested, not trusted blindly.
Common Regex Patterns Cheat Sheet
These are patterns developers ask for constantly. Use them as a starting point, then adapt them with the generator for your exact edge cases:
| What to match | Pattern | Example match |
|---|---|---|
| Email address | ^[\w.+-]+@[\w-]+\.[a-zA-Z]{2,}$ | ada@example.com |
| US phone number | ^\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}$ | (555) 123-4567 |
| Strong password (8+, upper/lower/digit) | ^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{8,}$ | Passw0rd123 |
| Hex color code | ^#([0-9a-fA-F]{3}|[0-9a-fA-F]{6})$ | #1E90FF |
| ISO date (YYYY-MM-DD) | ^\d{4}-\d{2}-\d{2}$ | 2026-07-05 |
| URL-friendly slug | ^[a-z0-9]+(?:-[a-z0-9]+)*$ | my-blog-post |
| IPv4 address | ^(\d{1,3}\.){3}\d{1,3}$ | 192.168.1.1 |