The AI Regex Generator turns matching requirements into regular expressions. Use it to extract emails, order IDs, URLs, dates, code fragments, or custom text patterns.
Describe what you want to match or exclude, and add sample text if possible. Mention case sensitivity, global matching, number ranges, separators, or boundary rules that must be preserved.
The result includes a regular expression, test examples, and a short explanation. Before using it in a project, test it with real data, especially for multilingual text, line breaks, and escaping rules.
A regex should be tested against both matches and non-matches. Describe the text, exclusions, and target environment, then use the expression and examples as a reviewable draft. Regex behavior can vary by language and runtime, so verify the pattern in your target environment before shipping it.
Input example
Requirement: Match valid email addresses. Support common personal and corporate emails (Gmail, Outlook, company domain emails). Allow uppercase and lowercase letters, digits, dots, underscores, and hyphens before the @ sign. Domain part allows multiple levels of subdomains. TLD must be at least two letters. Exclude invalid formats: missing @, empty local or domain part, or consecutive dots.
Flavor: JavaScriptOutput example
## Regular Expression
```javascript
/^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/
```
## Pattern Breakdown
- `^` — Match start of string.
- `[a-zA-Z0-9._%+-]+` — Local part: allows letters, digits, and . _ % + - characters; at least one.
- `@` — Required @ symbol.
- `[a-zA-Z0-9.-]+` — Domain part: allows letters, digits, dots, and hyphens; at least one.
- `\.` — Dot before TLD (escaped as literal).
- `[a-zA-Z]{2,}` — TLD: letters only, at least 2 characters.
- `$` — Match end of string.
## Match Examples
✅ user@example.com
✅ first.last@sub.example.co.uk
✅ user+tag@domain.com
❌ user@domain (missing TLD)
❌ @domain.com (empty local part)
❌ user..name@domain.com (consecutive dots)
## Edge Case Notes
- This pattern allows consecutive hyphens in the domain (e.g. user@dom--ain.com). To exclude, change the domain part to: `(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])\.`.
- TLD maximum length should be ≤ 63 characters in practice; consider adding {2,63} constraint.
- For strict form validation, it's recommended to use this regex for format filtering first, then send a verification email to confirm the address is genuinely valid.AI can produce a strong first draft, but regex behavior depends on the engine, flags, input encoding, and edge cases in your data. Treat the output as a starting point and test it with positive and negative examples.
Include the target format, allowed characters, length rules, whether the match should cover the full string, and examples of valid and invalid input. Specific constraints help prevent patterns that accidentally match too much.
Avoid nested greedy quantifiers on ambiguous input and test long strings that almost match. If the regex will run on user-controlled data, review it for catastrophic backtracking before using it in production.
Always test the generated RegEx against your specific production data to prevent edge-case bugs.