.tw is the Internet country code top-level domain (ccTLD) for the Republic of China, commonly known as Taiwan. The domain name is based on the ISO 3166-1 alpha-2 country code . The registry is maintained by the Taiwan Network Information Center (TWNIC), a Taiwanese non-profit organization appointed by the National Communications Commission (NCC) and the Ministry of Transportation and Communication. Since 1 March 2001, TWNIC has stopped allowing itself to sign up new domain names directly, instead allowing new registration through its contracted reseller registrars. , there are 17 registrars.
domain names can be registered at both the second and third level. Applicants are required to provide an email address for verification.
As of March 2017, around 8.31% of the .tw domains are served via secured HTTPS protocol, with the cPanel, Inc. Certification Authority being the most popular SSL certificate. Apache is the most popular web server, serving 47.60% of the .tw domains, followed by Microsoft-IIS serving 20.31% of the total .tw domains.
Domain names in Chinese characters may also be registered at the second level. Furthermore, any registrant of a standard domain name who has chosen a domestic registrar may automatically get two more domain names in Chinese characters in the following second-level domains: .tw, .tw and .tw. These second-level domains correspond to , and , respectively.
ICANN assigned two internationalized country code top-level domains (IDN ccTLDs) for Taiwan on 25 June 2010:
Since at least November 2015, the simplified suffix is a DNAME alias for the traditional suffix. As a result, any subdomain of the traditional .xn--kpry57d TLD automatically has a CNAME alias from the simplified .xn--kprw13d TLD. The traditional suffix is in active use.