Skip to main content

Internationalized Domain Names


Internationalized Domain Names (IDNs) enable people around the world to use domain names in local languages and scripts. IDNs are formed using characters from different scripts, such as Arabic, Chinese, Cyrillic or Devanagari. These are encoded by the Unicode standard and used as allowed by relevant IDN protocols.

ICANN has instituted the IDN Program to assist in the development and promotion of a multilingual Internet using IDNs. The program is primarily focused on the planning and implementation of IDN top-level domains (TLDs), including IDN country code TLDs and generic TLDs. The IDN Program also supports projects geared towards effective use of IDNs at the second-level of the Domain Name System, as guided by the community.

IDN Program Projects

Top-Level Domain Projects:

Root Zone Label Generation Rules (LGR) icon

Root Zone Label Generation Rules (RZ-LGR)

A community driven project aiming to define conservative mechanisms for introducing IDN TLDs into the Internet's Root Zone in a stable and secure manner.

IDN Variant TLD Implementation icon

IDN Variant TLD Implementation

A project to support the development of policy and procedures for implementing IDN variant TLDs.

LGR Toolset icon

LGR Tool

An application that enables users to create, use and manage IDN tables in the formal, machine-readable format, called Label Generation Rules.

IDN ccTLD Fast Track Process icon

IDN ccTLD Fast Track Process

Fast track process created by Internet community for evaluation of top-level IDN labels representing countries and territories.

Second-Level Domain Projects:

IDN Implementation Guidelines icon

IDN Implementation Guidelines

Recommended practices developed through a community-led process to reduce user confusion and promote consistent use of IDNs for registries implementing IDNs at the second level.

Second-level LGR References icon

Second-level LGR References

Reference second level LGRs, reviewed by experts and community, being provided to assist registries offering IDNs during Pre-Delegation Testing and the Registry Service Evaluation Process.

Learn More

Download the "Access Domain Names in Your Language" infographic:

Internationalized Domain Names allow people around the world to access domain names in their local languages

Download the "Emojis in Domain Names" document and learn why they create a security risk when used in domain names:

Emojis in Domain Names: A Security Risk for Everyone

Visit our Resources section for useful links and related documents.


Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as"""" is not an IDN."