Domain extensions

Availability comes from RDAP, the registry's own protocol, not from a reseller's search box. When a registry publishes no RDAP endpoint the report says so and links to the manual lookup instead of guessing.

Tier 1

Scanned on every plan, free included.

.comThe default commercial extension and still the one people type when they guess. A .com match is the strongest signal that a name is taken in practice, even when the trademark is free.
.coColombia's country code sold worldwide as a short stand-in for .com. Common with startups that lost the .com, at the cost of traffic leaking to the .com holder.
.ioRead as "input/output" by developers, which made it the default for technical products. Note that its underlying territory status has been under review, a political risk .com does not carry.
.appHTTPS-only by registry policy: every .app domain is on the browser preload list, so it cannot be served over plain HTTP. Reads as a product rather than a company.
.devHTTPS-only, like .app. Used for developer tools, documentation and engineering blogs rather than for a company's main address.
.aiAnguilla's country code, now priced as a premium extension because of the sector it names. Registrations are typically two years minimum and renew well above .com rates.
.netThe original infrastructure extension, now a general-purpose fallback. Widely recognised but reads as second choice next to a .com held by someone else.
.orgAssociated with non-profits, foundations and open-source projects. Open to anyone, but the association is strong enough that a commercial .org invites a second look.
.com.trThe commercial second level for Türkiye, and the address a Turkish customer expects from a Turkish company.
.trTürkiye's country code at the top level, opened to direct registration after TRABİS took over. Shorter than com.tr and increasingly used by brands that hold both.

Tier 2

Scanned on Pro and above.

Tier 3

Country and regional extensions, scanned on Pro and above.