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SI Now Means Super Intelligence. Here's What That Means for .si Domains

For 30 years, ".si" on the web meant one thing: Slovenia. As of September 2026, those two letters have a second meaning. This post covers what happened, why .si domains are suddenly in demand, what they cost, and the risks to weigh before you buy one.

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.si = Super Intelligence: the .si domain infographic The .si domain, Slovenia's country code since 1992, shown changing from the white, blue and red colors of the Slovenian flag into a glowing neural network. Since September 2026, .si also stands for super intelligence (SI). .si .si .si = SUPER INTELLIGENCE SLOVENIA · .si · 1992 SUPER INTELLIGENCE · SI · 2026 BUYSIDOMAIN.COM THE .si DOMAIN, REDEFINED
.si domain × super intelligence · BuySiDomain

What happened

At the UN General Assembly on Sept. 22, 2026, President Trump said all US government documents would from then on refer to artificial intelligence as "super intelligence," or SI, and said he hoped the rest of the world would follow. The next day, the State Department told diplomats in its international organizations bureau to use "super intelligence" instead of "artificial intelligence" in all communications. The internal email was titled "Change in Nomenclature AI to SI." (AP via ABC News, Breaking Defense)

On Sept. 29, 2026, Trump signed an executive order, "Inaugurating The Era Of Super Intelligence," directing executive-branch agencies to use "Super Intelligence" and "SI" instead of "Artificial Intelligence" and "AI" in official communications, websites, reports and policy documents. It also asks for a proposed federal legal definition of SI within 60 days. (TechRepublic, CNBC)

[TIMELINE] AI → SI · SEPTEMBER 2026

How “AI” became “SI” (super intelligence) in nine days

  1. Day 1

    Trump’s post

    On Truth Social, Trump uses SI for super intelligence.

  2. Day 2

    UN speech

    US documents will call AI super intelligence, or SI, Trump tells the General Assembly.

  3. Day 3

    State Dept email

    Change in Nomenclature AI to SI: diplomats told to say super intelligence.

  4. Day 9

    Executive order signed

    Inaugurating The Era Of Super Intelligence: agencies must use SI, not AI.

BUYSIDOMAIN.COMSOURCES: AP, BREAKING DEFENSE, TECHREPUBLIC

Sources: Breaking Defense, AP via ABC News, TechRepublic

One caveat applies. AI researchers already use "superintelligence" for a hypothetical system that would outperform humans intellectually across a wide range of tasks, so whether the rename sticks outside government is an open question. (Breaking Defense, TechRepublic)

Elon Musk has since backed the term: on 4 October 2026 he posted "No more AI. SI." on X. Here's what Musk said and what it means for .si domains.

Why this matters for .si domains

Anguilla's .ai became the default extension for AI companies largely because its two letters matched the term. Slovenia's .si could follow a similar path if "SI" catches on. Domain investors were already betting on this before the speech. For some time, investors had been discussing .si as shorthand for "superintelligence," much as .ai took off with AI startups, and treating it as an early buy comparable to .ai more than a decade ago. (Domain Name Wire)

Some critics say insiders got there first. We checked those claims against the registry and sales data in Did insiders cash in on .si domains before the "Super Intelligence" order?

The numbers so far

[DATA] .si DOMAINS · 2026

The .si domain market in four numbers

[01] Registered 202,673

.si domains registered as of September 2026

[02] Growth since June +16,336

more .si domains in September 2026 than in June (186,337)

[03] Biggest public sale $20,000

Recursive.si, sold to Recursive, an AI company working on superintelligence

[04] To register ~$12

per year for a new .si domain at most registrars

BUYSIDOMAIN.COMSOURCES: DYNADOT, HOSTINGER (2026)

Sources: Dynadot (registrations as of Sept 2026), Hostinger. Prices as of June 2026.
  • Registrations: Registry figures showed 202,673 .si domains registered as of September 2026, up 16,336 from 186,337 in June. (Dynadot)
  • Biggest public sale: Recursive.si sold for $20,000 to Recursive, an AI company working on superintelligence. The company still redirects the .si to its .com. (Dynadot)
  • Who is buying: A June 2026 review by Domain Name Wire found that domain investors accounted for most recorded .si sales this year.
  • Price: As of June 15, 2026, Dynadot charged $12.39 to register a .si. Hostinger lists it at $11.99 for the first year. (Dynadot, Hostinger)

.si vs .ai at a glance

[COMPARE] DOMAIN EXTENSIONS FOR AI

.si vs .ai domains at a glance

.siSlovenia · super intelligence
.aiAnguilla · artificial intelligence
Registration cost
About $12/yearTerms of 1 to 5 years
Much higherWith longer minimum terms
Total registered
About 203KSeptember 2026
1M+January 2026
Top public sale
$20,000Recursive.si
$1.2MBot.ai
Short names available
Many
Rare
Recognition as “AI”
Emerging
Established

Bars are to scale within each row. Dots are a rough visual rating, not measured data.

BUYSIDOMAIN.COMSOURCE: DYNADOT (2026)

Registrations and sales: Dynadot (.si as of Sept 2026, .ai as of Jan 2026)

Who can register a .si domain

  • Anyone, anywhere. Anyone can register a .si, with no requirement to live in or have a business presence in Slovenia. (Dynadot)
  • Terms of 1 to 5 years. Registration is instant, and both individuals and businesses can register. (101domain)
  • Limited privacy options. The .si zone does not currently offer a way to hide the domain owner's details. Check how your registrar handles WHOIS before you register. (NiceNIC)

Who should consider a .si domain

  • AI and "SI" startups that want a short, matching name.
  • Brands whose names end in "si," which makes for a natural domain hack.
  • Slovenian businesses, the original audience for .si.
  • Investors, but selectively.

[DECIDE] BEFORE YOU BUY

Should you buy a .si domain?

  1. Q1Are you an AI or SI startup?

    Yes

    →Buy a short .si that matches your name

    “SI” lines up with super intelligence. Register it at about $12 a year, and keep your main domain too.

    No

  2. Q2Does your brand name end in “si”?

    Yes

    →Grab the domain hack

    The .si spells the end of your name, so a brand called “Brandsi” becomes brand.si. Short and memorable.

    No

  3. Q3Are you a domain investor?

    Yes

    →Buy selectively

    Most 2026 sales were investor to investor. Pick short, brandable names and don’t pay hype prices.

    No

  4. You probably don’t need one, unless you’re a Slovenian business

    Rule of thumb: only buy a name you’d be glad to own even if “SI” never replaces “AI.”

BUYSIDOMAIN.COMSHOULD YOU BUY A .si DOMAIN?

Not financial advice.

The risks (read before you buy)

  • The market is mostly investors. Much of the 2026 activity has been investors trading with each other, so selling to an end user can take a long time. (Dynadot)
  • The rename may not stick. So far there are few signs that the tech industry plans to drop the term AI. (ThePrint)
  • Hype cools. If interest fades, speculative names lose value along with it. (Dynadot)
  • SEO trade-off. Unlike .ai and .io, .si isn't on Google's list of country-code domains it treats as generic. Google may therefore associate a .si site with Slovenia.

Rule of thumb: only buy a name you'd be glad to own even if "SI" never replaces "AI."

How to get a .si domain

  1. Check whether it's available to register. Our free .si domain checker looks it up in the registry. A new registration costs about $12 at most registrars.
  2. If it's taken, browse the aftermarket. You can see hand-picked .si names on BuySiDomain.
  3. Learn the basics first. Our complete .si domain guide covers the rest, and how to buy a .si domain compares registrar prices.

FAQ

What does .si stand for?

It's Slovenia's country-code domain, in use since 1992. Since September 2026, US government usage has also made "SI" shorthand for "super intelligence."

Is .si only for Slovenia?

No. Anyone in the world can register one.

How much does a .si domain cost?

About $12 per year to register a new one. Premium names on the aftermarket cost more.

Is .si a good investment?

It's early and speculative. Buy carefully and avoid paying hype prices.

Sources: AP via ABC News · Breaking Defense · TechRepublic · CNBC · Dynadot

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