Domain extensions: a complete guide and list of TLDs

A domain extension, also called a top-level domain (TLD), is the part of a domain name that comes after the final dot: .com, .org, .io, or any of the 3,500+ options now available. The extension you choose affects how your domain is perceived and trusted, what it costs to renew each year, and how it is treated by third-party technologies like search engines and AI systems. This guide covers every major type, what each extension signals, what to check on cost before you register, and how to browse all available extensions on TLD-list.

What is a domain extension?

A domain extension, sometimes called a website ending, is the suffix after the dot in a domain name. Technically, it is called a top-level domain (TLD); the term used by ICANN (Internet Corporation for Assigned Names and Numbers) and registrars worldwide.

In the domain name tld-list.com, "tld-list" is the second-level domain (SLD), and ".com" is the extension. Understanding what a domain name is helps clarify why the extension matters: it is the part of the address controlled not by you, but by a registry that sets the rules for who can register it and at what price.

Each TLD is administered by a registry. ICANN oversees the root zone (the master list of all valid extensions) and delegates management of each TLD to individual registries. Verisign, for example, manages .com; the Public Interest Registry manages .org. The 2012 ICANN new generic top-level domain (gTLD) program expanded the number of available extensions from around 22 to more than 1,500, introducing everything from .app and .ai to .london and .photography.

Types of TLD extensions: a full list of TLDs breakdown

There is many ways to classify domain name types. Domain extensions fall into five main categories. Each category has different rules on who can register, how many exist, and what they typically cost.

Domain name extension levels: TLDs, SLDs, and sub-level domains

Among all the domain parts, extensions are the top-level domain, which is the last section of a domain reading from right to left. Extensions are separated from the SLD with a dot. Now, there is an exception to that, and it is official SLDs on ccTLDs with sub-levels:

Sub-levels in ccTLDs

Not all ccTLDs have sub-level domains. The ones that do, sometimes called second-level ccTLDs, are a closed list defined by each country's registry. Importantly, a sub-level ccTLD is a separate registration from the base ccTLD. Owning tld-list.de does not give you tld-list.co.de; those are registered independently and may have different eligibility requirements and pricing.

The number of sub-level domains available varies by country. The UK, for example, has .co.uk, .org.uk, .net.uk, .me.uk, and others. Germany's .de has two: .co.de and .com.de. The US .us has none at all. To check whether a specific ccTLD has sub-levels, visit the TLD page for that extension:

ccTLD	Second-level examples	Notes
.uk	.co.uk, .org.uk, .me.uk, .net.uk	Widely used; .co.uk is the standard commercial choice
.au	.com.au, .net.au, .org.au, .edu.au	Australian sub-levels require local presence
.jp	.co.jp, .ne.jp, .or.jp, .go.jp	Japan uses a structured hierarchy by sector
.de	.co.de, .com.de	Fewer sub-levels; .de itself is widely used directly
.us	None	.us is a flat namespace; no official sub-levels
.ca	None	Canada uses .ca directly; no official sub-levels
Check out the rest of country code level domains, looking for the Sub-level table:

One important distinction

Some registrars or services offer addresses like {yourname}.de.com or {yourname}.us.com. These are subdomains of a premium SLD (de.com, us.com), not a registered ccTLD or sub-level extension. They work as domains, but they carry the limitations and dependencies of a subdomain rather than an independent registration. If you are evaluating one, understand whether you are buying a proper TLD registration or a subdomain of someone else's domain.

Domain extension meanings: what each extension signals

Before a visitor reads a word of your site, your domain extension communicates something about what they are about to find. These signals are audience-dependent and have shifted over time, but the associations are real.

Compare registration and renewal prices for any domain extension on TLD-list. Search any extension to see the full price breakdown by registrar; including what you will pay after year one.

The cost of popular domain extensions: what to check before you register

Every domain registration involves three cost components. Most registrars prominently advertise only the first.

• Registration; the first-year price to claim the domain. This is often discounted, sometimes dramatically. Promotional first-year pricing can be as low as $0.99 for some extensions and even be considered a "free domain" registration when part of a bundle.
• Renewal; the annual price to keep the domain after year one. This is the real ongoing cost, and it can be substantially higher than the registration price. A $0.99 first-year deal that renews at $35.00 costs more than a $12.00 .com over three years.
• Transfer; the fee to move the domain from one registrar to another. Transfer costs vary by extension and registrar. Some are free; others charge close to the renewal price.

The renewal price is what you pay every year after year one. TLD-list tracks registration, renewal, and transfer prices across 100+ registrars so you can compare the actual long-term cost before committing.

Note: Prices change over time and vary by registrar. Always confirm the current renewal price at tld-list.com before registering a domain.

How to choose the right domain extension

Choosing a domain extension involves four practical criteria:

1. Audience and geography. For a country-specific audience, a matching ccTLD can strengthen local search signals and increase trust. For a global audience, .com is the default safe choice. Choosing your domain extension should start with who you are trying to reach.
2. Industry signal. Choose an extension that matches what your audience expects. .io and .ai signal tech; .org signals non-profit; .store signals e-commerce. A relevant domain extension narrows the expectation gap before anyone reads a word of your site.
3. Long-term cost. Always compare renewal pricing, not just the registration promotional price. A $0.99 registration that renews at $40.00 per year costs more over three years than a $12.00 .com. Use tips for choosing a domain extension that focus on total cost of ownership, not just day one.
4. Availability. If your preferred name is not available in .com, consider a close-match ccTLD or a relevant new gTLD before settling for an extension that does not match your brand. A memorable domain name with a clear extension is worth more than a perfect SLD on an obscure or mismatched extension.

.com remains the safest default for most projects, especially for brands targeting non-technical audiences who may distrust unfamiliar domain endings. For tech products, developer tools, or AI companies, industry-standard extensions like .io or .ai can add brand credibility. For local businesses, a ccTLD matching the target country often outperforms .com on both trust and local search relevance.

Domain extensions list

TLD-list covers all 3,500+ domain extensions currently delegated in the DNS root zone. Each extension page shows registration, renewal, and transfer prices from the cheapest to the most expensive registrar, updated regularly. Every TLD page on TLD-list includes a full registrar comparison so you can find the right domain extension at the lowest verified price before you commit.

You can also browse by category or letter.

Frequently asked questions

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Editor team

Small crew of builders who believe a great idea should not be held back by a bad domain deal. We know this space inside out, from obscure new extensions to the registrar tricks that quietly inflate your renewal. We put that knowledge to work so you can spend less time worrying about domains and more time building the thing that matters.