When it comes to launching a website or a new brand, the domain extension you choose can make a big difference. In this post, we’ll explore the most popular TLDs (top-level domains) in use today—from the universally known .com to industry-specific favorites like .io, .ai, and beyond.
But before we dive into the list, it’s important to clarify what we mean by "popular."
We’re not focusing on country-code top-level domains (ccTLDs) that are used almost exclusively within their country of origin. For example:
.de for Germany
.cn for China
.mx for Mexico
These TLDs tend to be popular only within their respective countries and typically have restricted registration rules that don’t appeal to global users.
Instead, this post is about generic country-code TLDs—those originally designated to a country but now used worldwide thanks to open registration policies. Many of these extensions have been creatively repurposed by startups, developers, and creators to fit their brand or industry.
For example:
.la (originally for Laos) is used by companies and creatives in Los Angeles and Louisiana.
.fi (Finland) has found fans in fintech and crypto circles.
.to (Tonga) has been adopted by SaaS and Indie Hacker communities.
Let’s dive into the most widely used and respected domain extensions in the world today.
A TLD is the part of a domain name that comes after the dot—for example:
.com in example.com
.io in startup.io
They’re also commonly referred to as domain extensions, and they’re a vital part of how we navigate the internet.
Still the king. The .com domain extension remains the most recognized, most trusted, and most used TLD in the world.
Despite increasing scarcity, it’s often the first choice for businesses due to its global familiarity.
That said, many desirable .com domains are no longer available—either already in use or commanding high resale prices. This has led to the rise of newer, more niche alternatives.
Once considered the best fallback to .com, .net is still in use but has somewhat declined in popularity, especially among newer startups. It’s still used by some tech startups but despite what the extension was designed for, oddly, it is now more often used by smaller to moderate sized traditional, blue collar or mom & pop business types, also personal projects.
Initially intended for nonprofit organizations, .org has grown in appeal among educational, community-driven, open-source, and even for-profit platforms, including those in crypto and social innovation.
Short for "input/output" in computing terms, .io has become synonymous with startups, tech platforms, and software companies.
It’s clean, modern, and packs tech credibility. No wonder founders love it.
Originally Colombia’s ccTLD, .co was cleverly rebranded to mean "company." It’s short, snappy, and appealing to modern startups who want a strong brand without a bulky name.
As AI has exploded in popularity, so has the .ai extension. Originally the ccTLD for Anguilla, it’s now widely adopted by AI companies, research labs, and tools leveraging machine learning and automation.
While not as mainstream as .com or .io, these TLDs have carved out strong reputations within specific industries:
.gg – Popular in gaming but also growing among tech and crypto circles.
.app – Secured and backed by Google; ideal for mobile and web apps.
.dev – Also from Google, made for developers and engineering teams.
.tech – Straightforward and clean, a great fit for innovators and futurists.
.xyz – Adopted early by Web3 and crypto startups for its bold, disruptive vibe.
.so – Used creatively by Indie Hackers and solo founders.
.to – Repurposed by bootstrappers and SaaS founders due to its open registration.
There are hundreds of domain extensions out there, but only a handful manage to gain real traction across industries. When choosing your domain, consider:
Your industry
Your target audience
The brand identity you want to project
Availability of a strong, memorable name
Whether you’re looking to build the next unicorn or launch a side project, the right TLD can signal innovation, professionalism, or community alignment.