|Introduced||18 December 1995|
|TLD type||Country code top-level domain|
|Registry||Tonga Network Information Center (Tonic)|
|Sponsor||Government of Tonga|
|Intended use||Entities connected with Tonga|
|Actual use||Used for a varied assortment of sites, few related to Tonga. Often used for torrent websites, technology startups in Toronto, domain hacks, and unlicensed movie streaming websites.|
|Registration restrictions||Open to everyone, but use for spam or and some vulgar words are prohibited.|
|Structure||Registrations permitted at second level; some Tonga-related entities have domains at third level under labels like .gov.to|
|Dispute policies||Some trademarked names reserved; no other dispute policy|
.to is the Internet country code top-level domain (ccTLD) of the Kingdom of Tonga.
The government of Tonga sells domains in its ccTLD to any interested party. The .to ccTLD is administered by the Tonga Network Information Center (Tonic).
The .to top-level domain was widely commercialized in 1997 by the San Francisco company Tonic Corp. (www.tonic.to, founded by Eric Gullichsen and Eric Lyons) which would sell domains at $100 per unit. They operated with the approval of the Prince of Tonga. Network Solutions was already selling .to domains, but in a very chaotic fashion. Domain requests were processed by the Tongan consulate in San Francisco.
The top-level domain to itself had an A record and an HTTP server since at least 1998.
Because to is a common English preposition, it became popular to craft memorable URLs called domain hacks that take advantage of this; URL shortening/redirection services (e.g. go.to) are a popular use. Other domain hacks do not use the to as a preposition but rather as a syllable inside of a word, including Daniel J. Bernstein's website cr.yp.to, London web development company Potato p.ota.to.
"T.O." (tee-oh) is also a common nickname for Toronto, Ontario, Canada, and is used as a city domain. This domain is also used for the city of Torino (Turin), Italy, and also as a domain hack in Slavic languages (to meaning it or that) – such as the uploading service uloz.to ("ulož to" means "save it" in Czech and Slovak).
As the .to domains are purchased, all normal DNS operations are possible and registered sites are not required to display ads on behalf of the registrar. Some domains are free, like .edu.to, but only to real Tongan educational institutions. At this moment businesses registered in Tonga can also get free domains. People who sell on .to domains can claim a commission.
.to is one of the few ccTLDs that (officially) do not maintain a (public) WHOIS database providing registrant information. It is possible to contact domain registrants via tonic.to by typing the domain in the domain search field under "New Domain Name". This has resulted in limited popularity for the use of .to for websites involved in copyright infringement.
The .to registry allows the creation of emoji domain names. A former .to registrar, Register.TO, did support the search and registration of .to emoji domain names. Register.TO is no longer an authorized registrar for .to domain names, following the death of its owner in early February 2023 as stated by the NIC of Tonga according to an online review.