.si Domain: Why It's Trending & How to Register One (2026)

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).

Domain buyers moved within hours. Slovenia's .si registry recorded 3,515 new .si registrations in August and 46,066 in September (Domain Name Wire). The total went from about 190,000 .si domains on 4 September to 219,000 on 28 September, and the registry's own counter at Register.si showed 261,670 on 3 October 2026, with 12,399 registered in the previous 24 hours alone.

Most of that is speculation. Registrar data reported by TechCrunch puts the share of explicitly AI-related names at about 3%, and the registry's spokesperson was cautious about tying the jump to the executive order alone. A .si name is a short, cheap, brandable domain. It is not a guaranteed investment.

What Is a .si Domain?

.si is the country-code top-level domain (ccTLD) of Slovenia. 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.

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 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, which is why buyers from the US and India made up a large share of the September rush.

You don't buy from the registry itself. You register through one of the 92 accredited .si registrars (the registry's own count), 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: for individuals, the public WHOIS shows only the email address. Company details are public.

• Disputes: trademark conflicts go through the registry's alternative dispute resolution (ADR) procedure. The complainant has to show the name is confusingly similar to their mark, that you have no legitimate interest in it, and that you registered 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).

That is a fraction of what .ai costs. TechCrunch reports .ai at around $90 a year with a two-year minimum, which 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. Search the name in our free Domain Checker, which now includes .si next to 100 other extensions, 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 shown in WHOIS.

• Point the DNS. Set the nameservers at your registrar, then confirm them with our NS Lookup and watch the change spread with the DNS Propagation Checker.

• 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.

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. 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, who registered it with WHOIS Lookup (it reads the registry's official RDAP server), and whether its certificate is valid with the SSL Checker.

How to Transfer a .si Domain

To move a .si domain to another registrar, ask your current registrar for the authinfo code (the transfer password the registrar generates for the domain), then start the transfer at the new registrar and enter that code. The new registrar handles the rest with the registry.

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.