Does the domain extension affect SEO?

Very little. Google treats new extensions such as .dev and .app the same as .com and says keywords in the extension give no advantage. The exception is country code extensions, which signal the country of your audience.

Can anyone register a country code domain?

It depends on the country. Google's own guide warns that some countries restrict who can use their extension. Brazil's .com.br, for example, requires a Brazilian taxpayer ID, and foreign companies only get provisional registration through a local representative.

Why won't my .dev site open without HTTPS?

The .dev and .app extensions are on the browsers' HSTS preload list. Browsers only reach those domains over HTTPS, so the site needs a valid TLS certificate before it goes live.

Should I register both .com and my country code?

For a brand, it is usually worth it. You use one as the main address and redirect the other, so nobody registers the look-alike name and confuses your customers.

Which domain extension to choose

The extension is the last part of a domain, after the final dot: .com, .uk, .dev. Its technical name is TLD (top-level domain). It does not change how fast your site loads or how DNS works, but it does change who trusts the address, what you pay each year, who is allowed to register it and, in some cases, how the browser behaves.

Choosing well at the start saves you a domain migration later, which costs redirects, broken links and SEO work. This guide compares the most common options for developers and ends with a recommendation per scenario. If you are not sure what a domain is yet, see domain vs hosting.

Which criteria matter?#

Five questions settle most cases:

Where is your audience? One country, one region or the whole world.
Is the name available? Many short names are taken on .com and free on other extensions.
Who can register it? Some country code extensions require local documents.
What does it cost per year, and on renewal? The first-year price is misleading; compare the renewal price.
Are there technical rules? Some extensions only work over HTTPS.

Being easy to remember and type also counts. An address you have to spell out on the phone loses visitors when people forget a part of it.

When should you choose .com?#

.com is the best-known generic extension in the world. It is the natural choice for a product with an international audience, such as a public API, an open source library or a SaaS that sells in several countries.

Pros: everyone recognizes it, no documents required, every registrar sells it.

Cons: short names are hard to find. The price is not fixed: it is Verisign's wholesale cost plus the ICANN fee and the registrar's margin. And Verisign raises the wholesale price from time to time, within the cap set by its agreement with ICANN. The full math is in how much a domain costs.

When should you choose a country code?#

Country code extensions (ccTLDs), such as .uk, .de, .ca or .com.br, belong to a country. For a business that sells to one country, they tell visitors right away that you are local.

Pros: Google treats a country code as a strong signal that the site is meant for that country, according to its guide to multi-regional sites. Prices are often stable: Brazil's Registro.br, for example, charges a fixed yearly price for .com.br.

Cons: the same Google guide warns that some countries restrict who can use their extension. Brazil is a good example: .com.br requires a Brazilian taxpayer ID (CPF or CNPJ), and under the CGI.br rules foreign companies only get provisional registration through a representative established in the country. Check the rules of your country's registry before you plan around it. And the country signal cuts both ways: if your audience goes global one day, a country code still says "local" to everyone.

When do .dev or .app make sense?#

Both extensions are run by Google Registry and are generic, not tied to a country. .dev fits developer portfolios, documentation and tools; .app fits web and mobile applications.

Pros: many short names are still available, and the meaning is clear to a technical audience. For Google, new extensions are treated like any other generic one: the word in the extension neither helps nor hurts ranking, according to the Search Central blog.

Cons: both are on the browsers' HSTS preload list, which makes HTTPS mandatory on every connection, as the official .dev and .app pages state. In practice the browser refuses http://, and the site only opens once it has a valid TLS certificate. With an automatic certificate issuer (see how Let's Encrypt works), that is not a problem, but you cannot "push it live without HTTPS just to test". People outside tech also know these extensions less well.

One detail for local development: since .dev is a real extension, names like myapp.dev on your machine fall under that rule too. For local testing, use localhost or the .test extension, reserved for that purpose by RFC 2606.

How do the options compare side by side?#

Criterion	.com	Country code	.dev	.app
Type	Generic	Country	Generic	Generic
Ideal audience	Global	One country	Technical	App users
Who can register	Anyone	Depends on the country	Anyone	Anyone
Price	Wholesale plus registrar margin	Set by each country's registry	Varies by registrar	Varies by registrar
HTTPS required by browsers	No	No	Yes	Yes
Country signal on Google	No	Yes	No	No

Extensions such as .io and .co are technically country codes, but Google treats them as generic because people use them that way. The same Google documentation notes that this list may change.

Which extension fits each scenario?#

Shop, clinic, office or local service in one country: that country's code. If the name is also free on .com, register it and redirect.
SaaS, API or product sold internationally: .com. If it is taken, consider a different name before switching extensions.
Developer portfolio, tech blog, project documentation: .dev is a good choice, as long as HTTPS is ready before you publish.
App with a download page or a web version: .app, with the same HTTPS caveat.
Discord or Telegram bot with a simple dashboard: any option works; a subdomain from your host may be enough until the project grows.

If you are torn between two, compare the five-year renewal cost and ask three people from your audience which address they remember after hearing it once.

How do you protect your brand after choosing?#

If the name is your business brand, register the most likely variations (for example .com and your country code) and point the secondary ones to the main one with a 301 redirect. That stops someone from registering the look-alike version to confuse your customers.

Turn on auto-renewal and keep the registrant email up to date: an expired domain takes the site offline even when the server is fine. Then connect the domain to your app by creating DNS records at your registrar; the walkthrough is in how to use a custom domain.

How to do this on Square Cloud#

You choose and pay for the extension at the registrar of your choice, and the domain stays in your name there. Hosting does not include registering the name or its DNS zone.

From the Standard plan (from R$44.99 a month), you connect the domain to your application: the dashboard shows the DNS records you create at your registrar, with real-time validation status. TLS is automatic, which covers the HTTPS requirement of .dev and .app, and domains with accents (Punycode) are supported. The Hobby plan does not include custom domains.

While you decide on the extension, every web application gets a *.squareweb.app subdomain with HTTPS on every plan. See the details on custom domains.

Which domain extension to choose: .com, .dev, .app or a country code