These extensions found at the end of a URL or e-mail address signify a category of web site, such as commercial(.com) or the country from which the web site originates, such as Tuvalu(.tv).
| .ac | Top-level domain name for an educational network (same as .edu). |
| .ad | Andorra |
| .ae | United Arab Emirates |
| .af | Afghanistan |
| .ag | Antigua and Barbuda |
| .ai | Anguilla |
| .al | Albania |
| .am | Armenia |
| .an | Netherlands Antilles |
| .ao | Angola |
| .aq | Antarctica |
| .ar | Argentina |
| .arpa | A top-level domain name used for ArpaNet sites. |
| .as | American Samoa |
| .at | Austria |
| .au | Australia |
| .aw | Aruba |
| .az | Azerbaijan |
| .ba | Bosnia/Herzegovinia |
| .bb | Barbados |
| .bd | Bangladesh |
| .be | Belgium |
| .bf | Burkina Faso |
| .bg | Bulgaria |
| .bh | Bahrain |
| .bi | Burundi |
| .bj | Benin |
| .bm | Bermuda |
| .bn | Brunei Darussalam |
| .bo | Bolivia |
| .br | Brazil |
| .bs | Bahamas |
| .bt | Bhutan |
| .bv | Bouvet Island |
| .bw | Botswana |
| .by | 1. Belarus 2. Byelorussia |
| .bz | Belize |
| .ca | Canada |
| .cc | Cocos Islands - Keelings |
| .cf | Central African Republic |
| .cg | Congo |
| .ch | Switzerland |
| .ci | Cote D’Ivoire, or Ivory Coast |
| .ck | Cook Islands |
| .cl | Chile |
| .cm | Cameroon |
| .cn | China |
| .co | 1. Colombia 2. Top-level domain name for some commercial networks, same as .com. |
| .com | Pronounced "dot com." A top-level domain name used for commercial Internet sites in the United States. |
| .cr | Costa Rica |
| .cs | Czechoslovakia (former) |
| .cu | Cuba |
| .cv | Cape Verde |
| .cx | Christmas Island |
| .cy | Cyprus |
| .cz | Czech Republic |
| .de | Germany |
| .dj | Djibouti |
| .dk | Denmark |
| .dm | Dominica |
| .do | Dominican Republic |
| .dz | Algeria |
| .ec | Ecuador |
| .edu | A top-level domain name used for educational sites in the United States. |
| .ee | Estonia |
| .eg | Egypt |
| .eh | Western Sahara |
| .er | Eritrea |
| .es | Spain |
| .et | Ethiopia |
| .fi | Finland |
| .firm | An ending of an address for an Internet site for a business. Example: http://www.legal.firm. |
| .fj | Fiji |
| .fk | Falkland Islands/Malvinas |
| .fm | Micronesia |
| .fo | Faroe Islands |
| .fr | France |
| .fx | Metropolitan France |
| .ga | Gabon |
| .gb | Great Britain |
| .gd | Grenada |
| .ge | Georgia |
| .gf | French Guiana |
| .gh | Ghana |
| .gi | Gibraltar |
| .gl | Greenland |
| .gm | Gambia |
| .gn | Guinea |
| .gov | A top-level domain name used for a U.S. government site on the Internet. |
| .gp | Guadeloupe |
| .gq | Equatorial Guinea |
| .gr | Greece |
| .gs | South Georgia and South Sandwich Islands |
| .gt | Guatemala |
| .gu | Guam |
| .gw | Guinea-Bissau |
| .gy | Guyana |
| .hk | Hong Kong |
| .hm | Heard and McDonald Islands |
| .hn | Honduras |
| .hr | Croatia/Hrvatska |
| .ht | Haiti |
| .hu | Hungary |
| .id | Indonesia |
| .ie | Ireland |
| .il | Israel |
| .in | India |
| .int | A top-level domain name used for international institutions. |
| .io | British Indian Ocean Territory |
| .iq | Iraq |
| .ir | Iran |
| .is | Iceland |
| .it | Italy |
| .jm | Jamaica |
| .jo | Jordan |
| .jp | Japan |
| .ke | Kenya |
| .kg | Kyrgyzstan |
| .kh | Cambodia |
| .ki | Kiribati |
| .km | Comoros |
| .kn | Saint Kitts and Nevis |
| .kp | North Korea |
| .kr | South Korea |
| .kw | Kuwait |
| .ky | Cayman Islands |
| .kz | Kazakhstan |
| .la | Laos |
| .lb | Lebanon |
| .lc | Saint Lucia |
| .li | Liechtenstein |
| .lk | Sri Lanka |
| .lr | Liberia |
| .ls | Lesotho |
| .lt | Lithuania |
| .lu | Luxembourg |
| .lv | Latvia |
| .ly | Libya |
| .ma | Morocco |
| .mc | Monaco |
| .md | Moldova |
| .mg | Madagascar |
| .mh | Marshall Islands |
| .mil | A top-level domain name for a U.S. military site on the Internet. |
| .mk | Macedonia |
| .ml | Mali |
| .mm | Myanmar |
| .mn | Mongolia |
| .mo | Macau |
| .mp | Northern Mariana Islands |
| .mq | Martinique |
| .mr | Mauritania |
| .ms | Montserrat |
| .mt | Malta |
| .mu | Mauritius |
| .mv | Maldives |
| .mw | Malawi |
| .mx | Mexico |
| .my | Malaysia |
| .mz | Mozambique |
| .na | Namibia |
| .nato | A top-level domain name used for NATO sites. |
| .nc | New Caledonia |
| .ne | Niger |
| .net | A top-level domain name used for Internet administrative sites in the United States. |
| .nf | Norfolk Island |
| .ng | Nigeria |
| .ni | Nicaragua |
| .nl | Netherlands |
| .no | Norway |
| .nom | An ending of an address for a personal site on the Internet. Example: http://www.myplace.nom. |
| .np | Nepal |
| .nr | Nauru |
| .nt | Neutral Zone |
| .nu | Niue |
| .nz | New Zealand (Aotearoa) |
| .om | Oman |
| .org | A top-level domain name for organizational Internet sites in the United States. |
| .pa | Panama |
| .pe | Peru |
| .pf | French Polynesia |
| .pg | Papua New Guinea |
| .ph | Philippines |
| .pk | Pakistan |
| .pl | Poland |
| .pm | St. Pierre and Miquelon |
| .pn | Pitcairn |
| .pr | Puerto Rico |
| .pt | Portugal |
| .pw | Palau |
| .py | Paraguay |
| .qa | Qatar |
| .re | Reunion |
| .ro | Romania |
| .ru | Russian Federation |
| .rw | Rwanda |
| .sa | Saudi Arabia |
| .sb | Solomon Islands |
| .sc | Seychelles |
| .sd | Sudan |
| .se | Sweden |
| .sg | Singapore |
| .sh | Saint Helena |
| .si | Slovenia |
| .sj | Svalbard and Jan Mayen Islands |
| .sk | Slovakia |
| .sl | Sierra Leone |
| .sm | San Marino |
| .sn | Senegal |
| .so | Somalia |
| .sr | Suriname |
| .st | Sao Torme and Principe |
| .store | An ending of an address for an Internet site that is for a retail business. Example: http://www.variety.store. |
| .su | Former USSR |
| .sv | El Salvador |
| .sy | Syria |
| .sz | Swaziland |
| .tc | Turks and Caicos Islands |
| .td | Chad |
| .tf | French Southern Territory |
| .tg | Togo |
| .th | Thailand |
| .tj | Tajikistan |
| .tk | Tokelau |
| .tm | Turkmenistan |
| .tn | Tunisia |
| .to | Tonga |
| .tp | East Timor |
| .tr | Turkey |
| .tt | Trinidad and Tobago |
| .tv | Tuvalu |
| .tw | Taiwan |
| .tz | Tanzania |
| .ua | Ukraine |
| .ug | Uganda |
| .uk | United Kingdom |
| .um | U.S. Minor Outlying Islands |
| .us | United States |
| .uy | Uruguay |
| .uz | Uzbekistan |
| .va | Vatican City State |
| .vc | Saint Vincent and the Grenadines |
| .ve | Venezuela |
| .vg | British Virgin Islands |
| .vi | U.S. Virgin Islands |
| .vn | Viet Nam |
| .vu | Vanuatu |
| .web | An ending of an address for an Internet site that is about the World Wide Web. Example: http://www.resources.web. |
| .wf | Wallis and Futuna Islands |
| .ws | Samoa |
| .ye | Yemen |
| .yt | Mayotte |
| .yu | Yugoslavia |
| .za | South Africa |
| .zm | Zambia |
| .zr | Zaire |
| .zw | Zimbabwe |