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 the alpha-2 code the same as the country domain?

Almost always. Country-code top-level domains (ccTLDs) like .de or .jp are based on the ISO 3166-1 alpha-2 code. The notable exception is the United Kingdom, whose code is GB but whose domain is .uk.

What is the alpha-2 code for the UK?

The ISO 3166-1 alpha-2 code for the United Kingdom is GB, and the alpha-3 code is GBR, with numeric 826. The .uk domain is a historical exception that does not match the ISO code.

Do country codes ever change?

Yes, occasionally. When a country is renamed or formed, ISO updates 3166-1 — for example South Sudan was added as SS/SSD in 2011. This reference reflects the current standard codes.

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

ISO 3166-1 country codes

Search the official ISO 3166-1 country codes by name or by any of the three code forms. Developers, data analysts and operations teams use this standard for country fields in forms, APIs, spreadsheets and databases so that data stays consistent across systems.

How it works

The full code list is bundled with the page, so searching is instant and offline. Type a country name, a two- or three-letter code, or a numeric code, and the table filters to matching rows showing all three code forms side by side:

Form	Example (United Kingdom)	Typical use
Alpha-2	GB	Domains, web APIs, locale codes
Alpha-3	GBR	ISO documents, banking, sports
Numeric	826	Script-independent datasets

Example

Searching for Germany returns alpha-2 DE, alpha-3 DEU and numeric 276. Searching for the code JP jumps straight to Japan (JPN, 392). The numeric code is the same in any language or writing system, which is why statistical bodies prefer it.

Everything runs in your browser, with nothing uploaded.