Regex pattern library
Curated patterns grouped by use case. Test any pattern in the regex tester.
Validation
Email address
Common email validation pattern
/^[\w.+-]+@[\w.-]+\.[a-zA-Z]{2,}$/- Anchored to start of string (^).
- Anchored to end of string ($).
- Matches word characters (\w).
- Uses one-or-more quantifier (+).
ISO date (YYYY-MM-DD)
Calendar date
/^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$/- Anchored to start of string (^).
- Anchored to end of string ($).
- Matches digits (\d).
- Contains capturing or non-capturing groups.
Web & URLs
URL
HTTP/HTTPS URLs
/^https?:\/\/[\w.-]+(?:\.[\w.-]+)+[\w\-._~:/?#[\]@!$&'()*+,;=.]*$/i- Anchored to start of string (^).
- Anchored to end of string ($).
- Matches word characters (\w).
- Uses one-or-more quantifier (+).
- Uses zero-or-more quantifier (*).
- Uses optional quantifier (?).
- Contains capturing or non-capturing groups.
URL slug
Kebab-case slug
/^[a-z][a-z0-9]*(-[a-z0-9]+)*$/- Anchored to start of string (^).
- Anchored to end of string ($).
- Uses one-or-more quantifier (+).
- Uses zero-or-more quantifier (*).
- Contains capturing or non-capturing groups.
Data formats
IPv4 address
Dotted decimal IPv4
/^(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d\d?)$/- Anchored to start of string (^).
- Anchored to end of string ($).
- Matches digits (\d).
- Uses optional quantifier (?).
- Contains capturing or non-capturing groups.
UUID v4
Universally unique identifier
/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i- Anchored to start of string (^).
- Anchored to end of string ($).
Hex color
#RGB or #RRGGBB
/^#(?:[0-9a-fA-F]{3}){1,2}$/- Anchored to start of string (^).
- Anchored to end of string ($).
- Uses optional quantifier (?).
- Contains capturing or non-capturing groups.
Text processing
Digits only
One or more digits
/^\d+$/- Anchored to start of string (^).
- Anchored to end of string ($).
- Matches digits (\d).
- Uses one-or-more quantifier (+).