.si Domains: What They Are and Whether to Buy One for an AI Brand

A .si domain is Slovenia's country-code extension, and since late September 2026 it is also the extension people read as "super intelligence". Anyone in the world can register one. Whether you should depends on one question: is your brand built on the term, or are you buying because everyone else is?

What happened to .si

On September 22, 2026, President Trump told the UN General Assembly that the United States would call artificial intelligence "super intelligence", or SI. On September 29 an executive order told federal agencies to use "SI" in place of "AI".

Domain buyers had seen this pattern before. Anguilla's .ai went from a small island's country code to the default extension for AI startups. The two letters "SI" already belonged to Slovenia, so the same rush moved there.

The numbers from the registry, Register.si:

3,515 new .si domains in August 2026
46,066 new .si domains in September 2026
190,893 domains in total on September 4, and 250,769 on October 2

That is about thirteen times the usual monthly volume, most of it in the last nine days of the month.

Who can register a .si domain

Anyone. Slovenia dropped the local-presence requirement in 2008, so you do not need a Slovenian address or company. The registry is run by ARNES, the Academic and Research Network of Slovenia, and you buy through an accredited registrar.

Two practical points:

Not every registrar sells it. Some of the largest ones do not carry .si at all, so the registrar you already use may not be an option.
Check the price before you commit. Country domains are priced by each registrar, and a sudden rush tends to push prices up. Compare the first-year price and the renewal price.

Should you buy one?

It makes sense when

Your product is an AI product and you want the extension to say so, the way .ai does.
The name you want is gone on .com and .ai, and the .si version is short and clean.
You are comfortable owning a second extension next to your main one.

Think twice when

You are buying only to resell. Most names registered in a rush are never sold. The names that made money on .ai were short, real words, registered early.
Your customers are not in tech. Outside the industry, .si still means Slovenia, and many people will type .com from habit.
The whole brand depends on the term lasting. "SI" is a few weeks old as a label. If the wording changes again, a name like yourbrand.com still works and a name that leans on the extension does not.

.si next to .ai and .com

.com is still the extension people assume. If the .com is available at a normal price, take it first.
.ai is established. Buyers, investors and customers already read it as "AI company".
.si is the new option: far more good names are still free, and far fewer people recognise it yet.

A sensible setup for an AI brand is the .com or .ai as the main address, with the .si registered alongside if the name matters to you.

How to find an available .si name

The fast way is to generate names and check them in one step. The Domain Name Generator now includes .si for AI concepts: describe what you are building, and it suggests brandable names and checks each one against the Slovenian registry, so you only see names you can register today. If you are still naming the company itself, start with the Business Name Generator.

Three rules for picking the name:

Keep it short. Under 12 characters before the dot.
Make it work without the extension. If the name only makes sense with ".si" on the end, it is fragile.
Check the other extensions. If someone else owns the .com and the .ai of the same name, you will be sending them your traffic.

FAQ

Is .si only for Slovenia?

No. It is Slovenia's country code, but registration is open to anyone.

Is .si replacing .ai?

No. Registrations of .si jumped in September 2026, but .ai is still the extension most people associate with AI.

Will a .si domain rank worse in Google?

Country-code domains can be treated as targeting that country. Google has treated some country codes used as general-purpose extensions, such as .ai and .io, as generic. Whether .si gets the same treatment is not yet known.