IDN domains: domain names in every language

Internationalized domain names explained: how domains in Arabic, Chinese, Cyrillic and other scripts work, Punycode, the first IDN endings, and look-alike scam risks.

Internationalized domain names (IDNs) are domain names that use characters beyond the basic English letters a to z, such as Arabic, Chinese, Cyrillic, Hindi or accented letters like é and ü. They let billions of people use web addresses in their own language.

How IDNs work

The domain system was originally built for basic English letters, numbers and hyphens. To support every language, IDNs are converted behind the scenes into a special form called Punycode, which starts with xn--. Your browser shows the real characters, while the internet uses the Punycode version.

IDN endings

• IDN country codes: in April 2010, ICANN approved the first ones, for Egypt, Russia (.рф), Saudi Arabia and the United Arab Emirates. China's .中国 is another well-known example.
• IDN generic endings: the very first new gTLDs to go live in October 2013 were IDNs, including endings meaning "online" and "website" in Russian and "game" in Chinese.

Why they matter

• People can type addresses in the language and script they read every day.
• Local businesses can use names that match their real brand names.

Be careful: look-alike characters

Some letters in other scripts look identical to English ones, like the Cyrillic "а" and the English "a". Scammers have used this to create fake addresses that look like real brands, called homograph attacks. Modern browsers often show the Punycode version when scripts are mixed. Type important addresses yourself, and see our guide on avoiding domain typos.

Sources

• ICANN: IDN ccTLD delegations approved (April 2010)