What is the difference between alpha-2 and alpha-3 codes?

Alpha-2 codes are two letters (for example GB) and are used in domains and most web APIs. Alpha-3 codes are three letters (GBR) and are used where extra clarity is needed, such as ISO documents and some banking systems. Both come from the ISO 3166-1 standard.

What are the numeric country codes for?

The three-digit numeric codes are script-independent, so they work the same in any writing system. They are common in statistical and government datasets where letter codes might be ambiguous.

Is my search sent anywhere?

No. The full code list ships with the page and every lookup happens in your browser, so nothing you type is uploaded.

ISO Country Codes Reference

Look up ISO 3166-1 alpha-2, alpha-3 and numeric country codes.

ISO 3166-1 country codes

Search the official ISO 3166-1 country codes by name or by any of the three code forms: the two-letter alpha-2 code (used in web domains and most APIs), the three-letter alpha-3 code, and the three-digit numeric code.

Type a country, a code, or a number and the table filters instantly — entirely in your browser, with nothing uploaded.