.com vs .app vs .dev vs .io: which TLD for an app in 2026

The .com is taken. That's the normal case now, and it's worth knowing which alternatives are real choices and which are compromises.

.com

Still the default people type. If you can get it at registration price, get it. If it's parked with a four-figure asking price, ask what you're buying: type-in traffic mostly matters for consumer brands that will be spoken aloud. For an app that people find in the store, the domain is a landing page and a support address.

.app

Run by Google, launched 2018. It's on the HSTS preload list, which means browsers refuse to load it over plain HTTP. That's a feature: your site is HTTPS by default and there's no downgrade attack. For a mobile app it's the most descriptive extension there is. Downsides: some older corporate email filters still treat unfamiliar TLDs suspiciously, and a few people will add ".com" out of habit.

.dev

Also Google, also HTTPS-only. Reads as a developer tool or an API product. If your users are developers, it's often better than .com because it says what you are.

.io

The default for developer tools from 2012 to about 2022. Still respected, still expensive relative to others, and technically the country code for the British Indian Ocean Territory, whose sovereignty changed hands in 2025. The registry has said existing domains will keep working; the long-term status is a small risk worth knowing about.

.ai

Expensive, and increasingly a signal that a product is riding a trend. Fine if you actually are an AI company; otherwise it dates the brand.

.co, .net, .org, .xyz

.co works as a shorter .com and is widely trusted. .net and .org carry old associations that don't help a new app. .xyz is cheap and has a mixed reputation because of spam.

A rule of thumb

1. .com at registration price: take it.
2. Mobile app: .app, then .co.
3. Developer tool or API: .dev, then .io.
4. Never pay four figures for a .com before the app has users.

NameHQ checks the seven that matter for software and tells you when the .com is taken but .app or .dev is free.