HTTP & Networking
What is a TLD?
The top-level domain, the rightmost piece of a domain name, like `.com`, `.org`, `.io`, or `.dev`.
TLDs are managed by registries under contract with ICANN. The original generic TLDs (.com, .org, .net, .edu, .gov) have been joined since 2013 by hundreds of new gTLDs (.app, .dev, .io, .ai, .tech) and country-code TLDs (.us, .uk, .de, .co).
For most consumer use, TLD choice is purely branding, .com still carries authority, but Google explicitly does not weight TLDs in ranking. For developers, .dev and .app enforce HTTPS at the TLD level (they're on the HSTS preload list), which is a small but useful technical guarantee.
Country-code TLDs (ccTLDs) have geo-specific rules, some require local presence, some are restricted to citizens, some are operated as "fun" gTLDs (.io, .tv, .me). Always check the registry's rules before relying on a ccTLD for a serious property.
In the wild
- →
.com, generic, by far the most popular - →
.io, Indian Ocean ccTLD widely used by tech startups - →
.dev, operated by Google, HSTS-preloaded
FAQ
Does TLD affect SEO?
Google says no, except that ccTLDs signal regional intent (a .de domain ranks better for German-language queries in Germany).
What's the cheapest TLD?
It varies, but .com is usually $8-12/year at cost-price registrars (Cloudflare, Porkbun). Some new gTLDs run cheaper as promos but renew at higher rates.
Are .io domains safe?
Operationally yes, the registry is stable. The geopolitical questions about the British Indian Ocean Territory remain unresolved but haven't affected the namespace.
Related terms
The human-readable name that identifies a site on the internet, the part that maps to an IP address through DNS.
The Domain Name System, the distributed database that translates human-readable domain names into the IP addresses computers actually route to.
A prefix added to a parent domain to identify a separate section, app, or service, like `blog.example.com` or `api.example.com`.