.si vs .ai, .io and .com for an AI company

What each one actually is

• `.com` is a generic top-level domain. It carries no country signal.
• `.ai` is the country-code domain of Anguilla. It became popular with AI companies because the letters are the abbreviation for artificial intelligence.
• `.io` is the country-code domain of the British Indian Ocean Territory. It became popular with software and developer-tool companies.
• `.si` is the country-code domain of Slovenia, run by Register.si, part of ARNES. In AI circles “SI” is also used as shorthand for superintelligence.

So three of the four are country codes that people adopted for their look, not for their country. That is a common pattern on the web, and it is normal to use a country code this way. What differs is how search engines treat each one, which is the next section.

What Google says about country domains

Google's documentation on managing multi-regional sites says that country-code domains provide “a strong signal” that a site is explicitly intended for a certain country. It also says that geotargeting can improve rankings in the target country, but at the expense of results in other locales or languages.

The same page lists country codes that Google treats as generic, because users and site owners tend to see them as generic: .ad, .ai, .as, .bz, .cc, .cd, .co, .dj, .fm, .io, .la, .me, .ms, .nu, .sc, .sr, .su, .tv, .tk, .ws. `.ai` and `.io` are on that list. `.si` is not.

What this means for .si: according to Google's documentation, a .si site is treated as targeting Slovenia, and there is no setting that changes that for a country code that is not on the generic list. For a product aimed at a worldwide audience this is a genuine downside compared with .com, .ai or .io.

How big the effect is for your site is not something any documentation can tell you. Google describes a signal that favours the target country; the page does not say that such sites are excluded elsewhere. A Search Engine Journal report from July 2024 quotes Google's Gary Illyes saying that local domains tend to do better for users in that country because Search promotes local content, and that language targeting matters more than the domain type (source). Treat that as a third-party report, not as Google documentation.

Practical consequences if you choose .si: write in the language of your audience, make the content itself relevant worldwide, and if you serve several languages use hreflang annotations as Google's localized versions guide describes. Many products are discovered through their name, social posts and direct links rather than through generic search, where this matters much less. If organic search for broad terms is your main channel, weigh the downside seriously.

Email deliverability: the myth

A common belief is that mail from an unusual top-level domain lands in spam. We found no statement to that effect in the sender guidelines of Google or Yahoo: what they require is authentication. Gmail requires SPF or DKIM from every sender, and SPF, DKIM and a DMARC policy from those sending more than 5,000 messages a day to Gmail; Yahoo asks bulk senders for SPF, DKIM and DMARC as well.

That does not prove a new domain is treated like an old one: a brand-new domain with no sending history has to build a reputation whatever its ending. If you set up the records properly and send honest mail, .si is not a handicap that we know of. The email setup guide shows the records.

The trade-offs, side by side

• Recognition. In our view .com is understood by everyone, and .ai is understood by people in tech. .si is shorter and distinctive, but many people will read it as a Slovenian site, or ask what it is. Be ready to explain it.
• Search targeting. .com, .ai and .io are treated as generic by Google. .si is treated as Slovenia-targeted (see above).
• Availability of names. Which names are free differs per ending, and a name that is free today may be taken tomorrow. Never assume: search live.
• Registry stability. .si has been run by ARNES since it was delegated in 1992 (IANA record). For .io, The Register reported in October 2024 that if the ISO code for the territory were ever removed, ICANN policy would start a multi-year retirement process, and quoted ICANN and the registry operator on it (source). We have not confirmed later developments, so check the current status yourself.
• Meaning. .ai reads as artificial intelligence. .si reads as Slovenia to most people, and as superintelligence only to those who know the shorthand. See What does .si mean?.

How to choose

• If broad, worldwide organic search is your main channel and you want the least friction, a generic ending (.com, or .ai and .io, which Google treats as generic) is the safer choice.
• If you distribute through a community, social posts, documentation and direct links, a short memorable name matters more than the ending, and .si can work, with the geotargeting downside accepted.
• You do not have to pick one. You can register more than one ending and point them at the same site.

If you decide on .si, DomainSpace lets you check a name and see the price before you create anything. Whatever you pick, the disclosure stands: .si has no official connection to AI, and we are an independent reseller, not affiliated with the registry.