.com, .co, .io, .ai or .us: which domain extension should you pick?

The short answer: get the .com if you can

For most US small businesses, the best domain extension is .com. It is the ending people type without thinking, and the one they assume when they hear your business name.

It is also the biggest by far. Verisign, which runs .com, reported 166.6 million .com registrations at the end of the second quarter of 2026, out of 401.6 million domain names across every extension. That is more than 4 in 10 of all registered domains.

That size shapes habits. A customer who reads “Maple Street Bakery” on a truck tries maplestreetbakery.com first. If you are on .co, some of them land on someone else’s site, and emails typed with .com out of habit go to a domain you don’t own.

So start with the .com. Move to another extension only when the .com is taken and you can’t buy it at a fair price, or when a different ending fits who you are, such as .org for a nonprofit.

Renewal prices by extension

A domain registrar is the company you register the name through. Its first-year price is usually a sale. The renewal price is what you pay every year after that, for as long as you keep the name, so that is the number to compare.

How to read the table. All prices are per year, at renewal. Namecheap and Spaceship add a $0.20 yearly ICANN fee at checkout for some extensions. Porkbun’s prices already include ICANN fees.

About the Cloudflare column. Cloudflare sells domains at cost: it charges what the registry and ICANN charge, with no markup. It does not publish a public price list, so these figures come from cfdomainpricing.com, a third-party tracker, with data dated October 3, 2026.

About .ai. The .ai prices are per year, but .ai has a two-year minimum term, so your first purchase covers two years. At Namecheap that is $229.96 at the renewal rate.

Watch the gap between sale and renewal prices. At Namecheap, .io costs $34.98 for the first year and $75.98 a year after that. A .co is $7.98 the first year and $45.48 after.

What three years really costs

A domain is a bill for as long as your business runs, so look past year one. Here is three years at the cheapest renewal price among the four registrars, next to the same three years at Namecheap’s renewal prices. We used renewal prices for all three years to keep the comparison fair.

At the cheapest prices, an .io costs $120.06 more than a .com over three years, and an .ai costs $210.00 more. Where the $0.20 ICANN fee applies, add $0.60 over three years.

The .ai row hides one more catch. Because .ai is registered and renewed in two-year blocks, keeping it past year two means paying for years three and four together. By the start of year three you have paid for four years: $319.92 at Spaceship’s per-year price, or $459.92 at Namecheap’s.

The .com price goes up on November 1, 2026

Verisign announced that the wholesale fee it charges registrars for each new and renewed .com rises from $10.26 to $10.97 a year on November 1, 2026, about 7% more. Registrars pass it on to you.

Porkbun says its .com price will rise to about $11.81 on that date. Cloudflare passes registry prices through and says it will never add a surcharge to your renewal, so its .com should land near $11.17 ($10.97 plus the $0.20 ICANN fee). Namecheap and Spaceship had not published new .com prices when we checked in early October.

This does not change the verdict. Even after the increase, .com renews for much less than .co, .io or .ai at these registrars.

Each extension in a few lines

Extensions come in two kinds. Generic ones, such as .com, .net, .org and .app, are not tied to a country. Country-code ones, such as .co, .io, .ai and .us, belong to a country or territory. Some country codes are sold to anyone worldwide, and some have rules.

.com

A generic extension sponsored by Verisign, based in Reston, Virginia. It fits almost every business. Renewal: $9.98 to $18.48 a year at the four registrars above, before the November increase.

.net

The other big generic extension Verisign reports on, with 12.5 million registrations at the end of the second quarter of 2026. It works as a fallback when the .com is taken, but people will still type .com. Renewal: $11.20 to $18.58.

.org

Most people read .org as a nonprofit, a charity, a club or an open project. That is a convention, not a rule. It fits nonprofits, churches, associations and community groups, where it tells visitors what you are before they click. Renewal: $11.20 to $18.98.

.co

The country code for Colombia. IANA lists Colombia’s Ministry of Information and Communications Technologies as its sponsor, with CentralNic as the technical operator, and it is marketed to buyers worldwide. It is short and reads like “company.” The downside: it is one letter away from .com, so typed addresses and emails drift to the .com owner. Renewal: $30.00 to $45.48.

.io

The country code for the British Indian Ocean Territory. Its registry says anyone, anywhere can register one, and software companies use it widely. Since the Chagos sovereignty agreement, people have asked what happens to .io. We found no official statement on its future. Renewal: $50.00 to $75.98.

.ai

A country-code domain that AI and tech companies adopted. Its registry operator is Identity Digital, according to nic.ai. It has a two-year minimum for registration and renewal. Renewal: $79.98 to $114.98 a year, so $159.96 to $229.96 per two-year term. It fits an AI product that wants its name to say so. For a plumber or a law firm, it adds cost without helping customers find you.

.us

The country code for the United States, and the cheapest extension in our table at $6.48 to $10.98 a year. It has two rules most extensions don’t.

• The nexus rule. Under the federal nexus policy, you must be a US citizen, a permanent resident or someone living in the US; a company or group incorporated or organized in the US; or a foreign entity with a real (“bona fide”) presence in the US.
• No WHOIS privacy. Since August 29, 2019, registrars may not offer private or proxy registration on .us. Your contact details are public in the domain’s records. Use a business address and business email when you register.

.app and .dev

Both are run by Google Registry, and both are on the HSTS preload list. That is a list built into web browsers that forces every visit to use a secure HTTPS connection. A .app or .dev site without an SSL certificate won’t load.

That is a non-issue on modern website builders, which set up SSL for you. It fits apps, software and developer projects. Renewal for .app: $14.20 to $22.98. For .dev, Cloudflare lists $12.20 and Porkbun $12.87.

Does the extension affect SEO?

We have not found an official Google statement in our sources that ranks one generic extension above another, so we make no ranking claims here. SEO is mostly about the pages on your site, not the letters after the dot.

One thing is true by definition: a country-code extension can signal a country. .us says United States. .co and .io technically belong to Colombia and the British Indian Ocean Territory, even though they are sold worldwide. For a US business, a .com or .us keeps that signal simple.

Should I buy the .com too?

If you settle on another extension and the matching .com is available, buy it. At Spaceship’s $9.98 renewal, it costs less than a dollar a month. Point it at your main site so typed-in visitors still reach you, and set up email forwarding so stray emails do too. Namecheap, Porkbun and Cloudflare all offer free email forwarding.

Buying extra names to protect your brand is called a defensive registration. The common ones:

• The .com, when your main site is on .co, .io or .ai.
• A common misspelling of your name, as a .com.
• The .net or .us, if a competitor taking it would hurt you.

Here is the math for a main .com plus one misspelled .com and the .net. At Spaceship’s renewal prices that is $9.98 + $9.98 + $11.20 = $31.16 a year, or $93.48 over three years. At Namecheap’s renewal prices it is $18.48 + $18.48 + $18.58 = $55.54 a year, or $166.62 over three years.

Don’t overdo it. Every name is a bill that renews every year and one more account to keep secure. Most small businesses need one main domain and, at most, one or two defensive ones.

If the .com you want is taken

1. Add a word. Try getmaplebakery.com, maplebakeryco.com or maplebakeryshop.com.
2. Add your town. maplebakerydenver.com is longer, but it tells customers where you work.
3. Try .us or another extension. Expect some visitors and emails to go to the .com by habit.
4. Buy it from the owner. If the .com shows a parked page or a “for sale” notice, the owner may sell. Use a domain marketplace or broker so the money moves through escrow. Sedo’s broker service, for example, charges the buyer a $69 one-time fee plus 15% on success. Our guide to where to buy and sell websites covers domain marketplaces too.

What to do next

• New to domains? Start with domains 101 and what a domain name is.
• Choose where to register it with our guide to the best domain registrars.
• Connect the name to your site with domains and hosting explained.
• Paying too much at renewal? See how to transfer a domain.
• Budget the whole project with what a website really costs.

Sources

Registrar prices: Namecheap domains, Namecheap .ai, Porkbun domains, Porkbun .ai, Porkbun .com increase, Spaceship domains, Spaceship .com, Cloudflare Registrar, Cloudflare .com. Cloudflare per-extension prices: cfdomainpricing.com (third-party tracker). Registries and policy: Verisign Q1 2026 results, Verisign Domain Name Industry Brief, IANA Root Zone Database for .com, .co and .io, OpenSRS .ai policies, Google Registry for .app and .dev, NTIA usTLD nexus policy, usTLD privacy services policy. Names and disputes: USPTO Trademark Search, USPTO Basic Facts About Trademarks, ICANN UDRP, Sedo price list.