Example input and settings
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Common regex reference
Search regular expressions for common formats such as email, URL, IPv4, dates, UUIDs, colors and ports.
Search by format · Copy regexSearch patterns
These patterns check common text formats only; they do not prove that an address, account or business value is real or valid.
NameRegular expressionDescription
Email format
^[^\s@]+@[^\s@]+\.[^\s@]+$Basic email text format; not mailbox verificationHTTP(S) URL
^https?:\/\/[^\s/$.?#].[^\s]*$Requires an http:// or https:// prefixIPv4 address
^(?:(?:25[0-5]|2[0-4]\d|1?\d?\d)\.){3}(?:25[0-5]|2[0-4]\d|1?\d?\d)$Four decimal octets from 0 to 255ISO date
^\d{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])$YYYY-MM-DD shape with basic month and day ranges24-hour time
^(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d)?$HH:mm or HH:mm:ss from 00:00 to 23:59:59Integer
^[+-]?\d+$Optional sign followed by digitsDecimal number
^[+-]?(?:\d+\.?\d*|\.\d+)$Common decimal notation without exponentHexadecimal value
^(?:0x)?[0-9a-fA-F]+$Optional 0x prefix and hexadecimal digitsUUID
^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$Canonical hyphenated UUID versions 1 through 8HEX color
^#(?:[0-9a-fA-F]{3}|[0-9a-fA-F]{6}|[0-9a-fA-F]{8})$3, 6 or 8 hexadecimal color digitsHostname
^(?=.{1,253}$)(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)*[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?$DNS-style labels; no reachability checkTCP/UDP port
^(?:0|[1-9]\d{0,3}|[1-5]\d{4}|6[0-4]\d{3}|65[0-4]\d{2}|655[0-2]\d|6553[0-5])$Decimal port number from 0 to 65535Username format
^[a-zA-Z][a-zA-Z0-9_-]{2,31}$3 to 32 characters, beginning with a letterSemantic version
^(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)\.(?:0|[1-9]\d*)(?:-[0-9A-Za-z.-]+)?(?:\+[0-9A-Za-z.-]+)?$Core SemVer with optional prerelease and build textBlank line
^\s*$A line containing whitespace onlyCommon regex reference
Search regular expressions for common formats such as email, URL, IPv4, dates, UUIDs, colors and ports.
Check the input format and options with this example before using your own data. Random values, file sizes and presentation vary with the input and settings.
What to check in the result
^(?:(?:25[0-5]|2[0-4]\d|1\d{2}|[1-9]?\d)\.){3}(?:25[0-5]|2[0-4]\d|1\d{2}|[1-9]?\d)$