US
United States
ISO 3166 Country Code
North America
Country Codes
Alpha-2 Code (ISO 3166-1 alpha-2)
US
Alpha-3 Code (ISO 3166-1 alpha-3)
USA
Numeric Code (ISO 3166-1 numeric)
840
Common Usage
HTML lang attribute
<html lang="us">
URL locale parameter
https://example.com/us/
JavaScript/TypeScript
const country = "US"; const countryName = "United States";
API Response (JSON)
{
"country": "US",
"countryName": "United States",
"alpha3": "USA",
"numeric": "840"
}ISO 3166 Standard
ISO 3166 is the international standard for country codes. The alpha-2 code (US) is the most commonly used format for domain names, language tags, and internationalization. The alpha-3 code (USA) is used in shipping, banking, and official documents. The numeric code (840) is language-independent and useful for systems with character encoding limitations.