.si Domain: Country, Rules, Price & Why It's Trending

Why .si Domains Are Trending in 2026

On 22 September 2026, President Donald Trump told the UN General Assembly that the US government would call artificial intelligence "super intelligence", or SI. On 29 September he signed an executive order telling federal agencies to use "SI" and "super intelligence" in place of "AI" and "artificial intelligence" (TechCrunch).

Buyers moved even before the speech. Registrations began rising on 19 September, after a Truth Social poll on a new name for AI, and Netcraft found that daily .si registrations overtook .ai within 25 hours of the UN speech (Netcraft). Slovenia's registry recorded 3,515 new .si registrations in August (Domain Name Wire) and 46,066 in September (Register.si's counter, reported by CircleID). DomainNameStat data in the same report counted 17,621 new .si names against 7,209 .ai names between 23 and 29 September.

The rush peaked in early October. The registry's own counter at Register.si showed 330,073 .si domains on 7 October 2026, with 18,498 registered in the previous 24 hours, more than five times as many as in the whole of August. By 26 October it showed 454,320 .si domains, with 2,548 new in the previous 24 hours.

Much of it is speculation. Netcraft found that about 52% of the .si names registered at Dynadot between the poll on 19 September and the speech on 22 September were listed for resale there, and that more than 44,000 .si names, 22% of the zone at the time, share their name with an existing .ai domain. A .si name is a short, cheap, brandable domain. It is not a guaranteed investment.

What Is a .si Domain, and Which Country Is It?

.si is the country-code top-level domain (ccTLD) of Slovenia, the small EU country between Italy, Austria, Hungary and Croatia. It was introduced on 1 April 1992 (Wikipedia) and is run by Register.si, the registry operated by ARNES, the Academic and Research Network of Slovenia. So when people ask who owns .si, the answer is a Slovenian public institution, not a private company.

You register names directly under .si (yourname.si). There is no second level such as .com.si that you have to use, so the shortest, cleanest version of a name is the one you get.

Long before the super intelligence rush, .si was a favourite for domain hacks. In Slovene, "si" means "you are", which gives names like zadovoljna.si ("you are pleased"). In Spanish, "sí" means "yes", and in Italian "si" means "yes" or "oneself". The open-source video platform Jitsi runs its public meetings on meet.jit.si.

Who Can Register a .si Domain?

Anyone. The registry's General Terms and Conditions define a domain holder simply as "a natural or legal person". You do not need a Slovenian address, citizenship or company, and TechCrunch reported that more than half of Hostinger's .si buyers in the rush were in the US and India.

You don't buy from the registry itself. You register through one of the 103 accredited .si registrars (the registry's count on 26 October 2026), or through a reseller that works with one.

.si Domain Name Rules

The rules come from the registry's General Terms. They are more relaxed than many ccTLDs, and a few of them are worth knowing before you search:

• Length: 2 to 63 characters, so two-character .si names are allowed if they are still free.
• Characters: letters a to z, digits 0 to 9 and hyphens. A name can't start or end with a hyphen, and can't have hyphens in both the 3rd and 4th positions.
• Accented letters (IDN): the Slovene č, š and ž, plus a long list of accented Latin letters such as á, é, í, ñ, ü, ć and đ (full list). A Spanish "sí" can keep its accent.
• Registration term: 1, 2, 3, 4 or 5 years per registration or renewal.
• WHOIS privacy: the registry's public WHOIS and RDAP servers show "NOT DISCLOSED" for the holder, even for companies. The lookup on register.si's website shows a company's details, and for an individual only an email address.
• Disputes: trademark conflicts go through the registry's alternative dispute resolution (ADR) procedure. The complainant needs a right valid in Slovenia (a trademark, a company name or a personal name) and has to show the name is confusingly similar to it, that you have no legitimate interest in it, and that you registered or are using it in bad faith.

How Much Does a .si Domain Cost?

The registry charges registrars about €10 a year per .si domain (Domain Name Wire), and each registrar sets its own retail price on top. At Hosting.com, a .si domain costs $14.99 for the first year and $23.99 a year after that (checked on 3 October 2026). Across the big registrars, first-year prices run from about $10 to $20, and we compare them in our .si domain price guide.

That is a fraction of what .ai costs. Porkbun lists .ai at $82.70 a year, and .ai has a two-year minimum, so at Porkbun the cheapest way in is $165.40 upfront. That price gap is a big part of why buyers chasing the "SI" label went for .si first.

Always look at the renewal price, not just the first-year deal. You pay the renewal every year you keep the name, so over five years it matters far more than the discount.

How to Register a .si Domain (Step by Step)

Registering a .si domain takes about five minutes. These steps also cover what to do after you buy it, which is where most new owners trip up:

• Check availability. Type the full name, such as brand.si, into our free Domain Checker, which asks the .si registry whether it's taken, or search directly at Hosting.com.
• Rule out trademarks. Skip names that match a brand you don't own. A .si dispute goes through the registry's ADR procedure, and losing it means losing the domain.
• Pick a registrar and a term. Register through an accredited registrar or a reseller such as Hosting.com, for 1 to 5 years. A longer term locks in the price and protects you if a renewal email gets missed.
• Use a working email address. The registry treats your email as the main way to reach you about renewals and transfers, and for individuals it is the only contact detail the register.si lookup shows.
• Point the DNS. Set the nameservers at your registrar, then confirm them with our NS Lookup and check the records from public DNS with DNS Lookup.
• Turn on DNSSEC if your DNS host offers it. .si supports DNSSEC (Register.si DNSSEC), which protects your records from being forged in transit.

Is a .si Domain Good for SEO Outside Slovenia?

This is the part most .si buyers miss. Google says country-code domains "provide a strong signal to both users and search engines that your site is explicitly intended for a certain country". It keeps a short list of ccTLDs that it treats as generic, like .com. That list includes .ai, .io, .co, .me and .tv, but not .si (Google Search Central).

So Google treats a .si website as aimed at Slovenia. A .si site can still rank in other countries with strong content and links, but it starts with a geographic signal pointing the wrong way if your customers are in the US, India or anywhere else.

The practical rule: if you are building a global product and organic search matters, keep your main site on .com or a generic ccTLD such as .ai or .io, and use the .si name as a short brand, a redirect or a campaign domain. If your audience is in Slovenia or speaks Slovene, .si is the natural choice.

.si vs .ai: Which Should You Pick?

Both are country domains used for their letters rather than their country: .ai belongs to Anguilla, .si to Slovenia. Here is how they compare on the points that matter for a new project:

Many teams will end up with both: the .ai or .com as the main site, and the matching .si registered to protect the name and redirect to it. Our full .si vs .ai comparison covers price over five years, SEO, resale and typosquatting in detail.

Is a .si Domain Safe?

The extension itself is a normal national domain, run by Slovenia's academic network and supporting DNSSEC. A domain extension is not safe or unsafe on its own. The site behind it is.

Be more careful during the rush, though. Netcraft had seen little phishing on .si by early October, but it flagged an obvious risk: S and A sit next to each other on a QWERTY keyboard, so brand.si is a ready-made typo of brand.ai. Tens of thousands of brand-new .si names are in the hands of speculators, and fresh domains on a hot trend are a classic phishing tool.

Before you trust an unfamiliar .si site, check how old it is with our Domain Age Checker, its dates and registrar with WHOIS Lookup (the registry's RDAP server doesn't show holders; for the holder, use the lookup on register.si), and whether its certificate is valid with the SSL Checker. If you own a brand on .ai or .com, registering the matching .si is cheap insurance.

How to Transfer a .si Domain

To move a .si domain to another registrar, choose an authinfo password and set it on the domain through your current registrar or its control panel (the registry's site has a calculator that turns it into the SHA-256 digest registrars take). Then start the transfer at the new registrar and give it the plain password. The new registrar handles the rest with the registry (Register.si).

Changing the holder, for example when you sell the name, is a separate step. The registry's General Terms require the agreement of both the current and the new holder. If you buy a .si name from a speculator, make sure the holder change is done properly, not just the registrar transfer.