There are over 1,500 top-level domain extensions available today. Most of them are garbage. Nobody is typing "mybusiness.accountant" into their browser. But a handful of the newer TLDs have actually earned legitimate traction, and knowing which is which can save you money and credibility.

.io -- The Developer Standard (With a Catch)

.io has been the go-to for tech startups since around 2014. It is short, it looks techy (input/output), and enough major companies use it (draw.io, socket.io, itch.io) that regular people kind of recognize it now. Pricing runs $30 to $50 a year at most registrars.

The catch: .io is technically the country code for the British Indian Ocean Territory, and there have been periodic concerns about the UK government potentially giving up sovereignty over those islands. If that happened, the TLD could theoretically be retired (like .su after the Soviet Union). This is probably not going to affect you, but it is worth knowing.

.dev -- Google's Gift to Developers

Google owns this one and requires HTTPS by default (it is on the HSTS preload list). That means you cannot accidentally serve your .dev site over plain HTTP, which is actually a nice security feature. It has solid adoption among developer tools and portfolios. At $12 to $15 a year, it is reasonably priced too.

If you are building something aimed at developers, .dev is a strong choice. It is less overused than .io and the forced HTTPS is a genuine benefit rather than a gimmick.

.app -- Underrated for Mobile

Also Google-owned, also HTTPS-required. It never quite took off the way Google probably hoped, which means there is actually good availability. If you are building a mobile app and the .com is taken, .app communicates exactly what you are offering. "Taskflow.app" reads cleaner than "taskflowapp.com" in my opinion.

.ai -- The Hype Extension

Every AI company and their cousin is buying .ai domains right now. Availability is getting scarce for anything short and catchy. Prices are steep -- expect $70 to $100+ per year for registration, and premium names go for thousands. It is the country code for Anguilla, meaning a tiny Caribbean island is making serious money off the AI boom.

Worth it if you are genuinely in the AI space and plan to keep the domain long-term. Not worth it if you are trying to look trendy -- the "slap AI on everything" wave will recede eventually.

.co -- The Quiet Contender

.co has been around long enough that most people recognize it. Twitter used t.co for their link shortener, which helped with awareness. It works for startups that cannot get the .com but want something that feels "close enough." Affordable at around $25 a year.

The main risk is people accidentally typing .com instead. If your competitor has the .com of your .co domain, you are sending them free traffic. Check that before you commit.

.xyz, .cc, and the Rest

.xyz got a huge boost when Google restructured as Alphabet and used abc.xyz. But outside of tech circles, it still looks unfamiliar to most people. It is dirt cheap ($1 to $5) which makes it good for experiments and side projects.

.cc was popular in the early 2000s, fell out of favor, and has quietly come back for short brandable names. At $10 to $15 a year, it is fine for niche projects but I would not build a primary brand on it.

My Actual Recommendation

If the .com is available and reasonable, buy it. If not, go .co for consumer brands or .dev/.io for developer tools. Skip everything else unless you have a specific reason. And whatever you choose, check availability across all TLDs before you commit -- you might be surprised at what is open.