Tiny Online Tools
Learn & Use Regex Patterns from a Curated Library
Regex is powerful but intimidating. A pattern like (?:[a-z0-9!#$%&'*+/=?^_{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_{|}~-]+)*)@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?) looks like gibberish until you understand each token. This Regex Generator combines a library of proven patterns with an interactive explainer, so you learn how patterns work while solving real problems.
Search for a pattern you need (email, phone, date, URL, etc.), see working examples, understand what each part does, and copy the pattern to your code. Or paste your own regex to get a token-by-token explanation.
Curated Pattern Library
The tool includes common regex patterns for:
- Email Addresses: RFC-compliant email validation
- URLs & Web Addresses: HTTP/HTTPS URLs with various domains
- Phone Numbers: US, international formats
- Dates & Times: ISO, US format, timestamps
- IP Addresses: IPv4 and IPv6
- Passwords & Security: Password strength requirements
- Usernames: Valid username formats
- Credit Cards: Basic format validation
- Postal Codes: ZIP codes, international formats
- Hex Colors: CSS color codes
Patterns are battle-tested—they're not perfect (email validation via regex is famously imperfect), but they're practical and work for most use cases.
Token-by-Token Explanations
Select any pattern and see a breakdown of each token:
^anchors the start[a-z]+matches one or more lowercase letters\\dmatches a digit*means zero or more(group)captures matched content{n,m}quantifier: match between n and m times- And so on
Each token displays its plain-English meaning, helping you understand how the pattern works and how to modify it for your needs.
Explain Your Own Patterns
Paste any regex into the "custom pattern" box and get an instant explanation. This is invaluable for:
- Understanding regex you found online
- Debugging patterns that don't work as expected
- Learning how other developers wrote patterns
- Verifying your regex does what you think it does
Copy Patterns Instantly
Find a pattern you need? Copy it with one click and paste directly into your code.
Common Developer Use Cases
Form Validation: Find email, phone, or password regex patterns to use in form validation. Copy and paste into your HTML5 input pattern attributes or JavaScript validation code.
Input Validation: Validate user input matches expected format before processing. Email, username, postal code—find the pattern and validate against it.
Data Extraction: Use regex patterns to extract specific data from strings. Find a phone number regex, use it to extract phone numbers from text blocks.
Search & Filter: Write regex to search large datasets for records matching a pattern. Find items with valid email addresses, IP addresses, or specific formats.
Learning Regex: New to regex? Browse patterns, understand tokens, and gradually build your regex skills.
Debugging Failed Validations: Your regex doesn't match valid input? Paste it here to see the token breakdown and spot the problem.
Regex Portability: Some languages have slightly different regex syntax. The library focuses on JavaScript/PCRE-compatible patterns that work in most languages.
Search the Library
Quickly find what you need by searching the library. Type "email," "date," "phone," or similar to filter patterns.
Work Offline
The pattern library and explanations load entirely in your browser. Work offline without internet access once loaded.
Perfect Starting Point
Rather than writing regex from scratch, start with a proven pattern and customize it. This saves time and reduces bugs from untested regex.