The 12 Best Domain Extensions for Tech Startups in 2025 (And 3 to Avoid)

You’re launching a tech startup. You've got the idea, the team, and the drive. But when you go to register your domain, you discover `YourPerfectName.com` was sold in 1999.

Don't panic. In 2025, your Top-Level Domain (TLD) is more than just an address—it's a powerful signal about your brand. Choosing `.io` or `.ai` isn't a compromise; it's a strategic move that can instantly tell the world who you are.

But which one is right? Here are the 12 best domain extensions for tech startups, ranked by their modern brand value.

Tier 1: The New Tech Standards

These are no longer "alternatives." For many in tech, these are the new default. They are short, memorable, and carry strong industry trust.

1. .ai (The AI King)

Originally the country code for Anguilla, `.ai` has been universally adopted as the TLD for "Artificial Intelligence." If your startup's core product is an AI tool, a machine learning platform, or a robotics company, using `.ai` is the single fastest way to communicate that.

2. .io (The Developer's Favorite)

Like `.ai`, this country code (British Indian Ocean Territory) was adopted by the tech world for "Input/Output." It has been the darling of SaaS companies, open-source projects, and developer tools for years. It's respected, recognized, and signals you are a core-tech company.

Tier 2: The Niche Specialists

These domains are less flexible but incredibly powerful if your product fits the description. They act as a label that qualifies your business instantly.

3. .dev (The Secure Developer Hub)

Owned by Google, `.dev` is for "developer." It's perfect for internal tools, developer platforms, and open-source projects. A key feature: `.dev` is on the "HSTS preload list," meaning it requires HTTPS to function. This makes it a secure choice by default.

4. .app (The Mobile App)

Also owned by Google and requiring HTTPS, `.app` is the single best TLD for a mobile application's landing page. It's clear, descriptive, and perfect for marketing your software.

5. .tech (The Industry Label)

A clear, no-nonsense extension. While a bit broader than `.ai` or `.dev`, it's a great "catch-all" for any company in the technology space, from hardware startups to IT consultancies.

Tier 3: The Modern & Versatile

These TLDs are excellent, flexible alternatives to `.com` that signal you are a modern, forward-thinking company.

6. .xyz (The New Generation)

Used by many Web3 and next-gen tech companies (including Alphabet, Google's parent company: `abc.xyz`), this TLD is a bold, modern, and versatile choice. It's a great option if you want to signal that you're building something new and different.

7. .co (The .com Challenger)

Originally for Colombia, `.co` is now a globally recognized TLD for "company" or "corporation." It's the most common and trusted alternative when your `.com` is taken. It's short, professional, and understood everywhere.

8. .cloud (The SaaS Platform)

If your entire business is built on cloud infrastructure or you're a B2B SaaS platform, `.cloud` is a highly descriptive and relevant TLD. It clearly communicates the nature of your service.

9. .so (The Short & Sweet)

A newer kid on the block (Somalia's ccTLD), `.so` is being adopted by startups for its short, clean look. Companies like Notion have used `notion.so` (though they later moved to `.com`). It's trendy and memorable.

Tier 4: The Classics (Still a Great Choice)

10. .com (The Gold Standard)

Let's be clear: if you can find a short, brandable `.com`, get it. It is still the most trusted and recognized TLD in the world. But don't add hyphens or extra words to get one. A clean `.io` is far better than a clunky `.com`.

11. .org (The Mission-Driven)

If your tech startup is an open-source project, a non-profit foundation, or a mission-driven company, `.org` is perfect. It signals trust and a community focus.

12. .net (The Network)

One of the original TLDs, `.net` (for "network") has faded in popularity but is still a valid choice for networking, infrastructure, or platform-based companies. It's often more available than `.com`.

3 Domain Extensions Startups Should AVOID

Just as important as what to pick is what *not* to pick. Choosing the wrong TLD can make your brand look unprofessional or, worse, untrustworthy.

1. Obscure Country Codes (.cc, .ly, .tv)

While `.ai` and `.io` "graduated" to global status, most ccTLDs have not. Using a `.ly` (Libya) or `.cc` (Cocos Islands) can be risky. These domains can be subject to the political or registry instability of their host country. They also just confuse users. Is `bit.ly` "bit.ly.com" or just "bit.ly"?

2. "Spammy" or Outdated TLDs (.biz, .info, .us)

These extensions were popular in the early 2000s and were heavily abused by spam and low-quality websites. Right or wrong, they now carry a negative perception and can make your cutting-edge startup look dated and untrustworthy.

3. Overly Long TLDs (.software, .technology, .solutions)

These TLDs are just too clunky. No one wants to type `YourName.technology`. They are hard to remember, hard to type, and offer no real brand value. The whole point of a TLD is to be a short, memorable suffix. Stick to the shorter options.

Final Verdict: Your TLD is Your First Impression

Your domain extension is the first signal you send to a user. A great TLD, like a great business suit, inspires confidence and shows you belong. The good news? You have more (and better) options than ever.

Choose an extension that tells your brand's story. Are you an `.ai` pioneer, a `.dev` builder, or a `.xyz` visionary? Now that you know your options, go find the name that fits.