.com vs .co.uk vs .io vs .dev: How to Pick a TLD

The part after the dot is a signal — about where you are, what you do and how established you look — and a recurring cost. There are over 1,500 top-level domains now, and most are the wrong choice for a business. This is how the ones people actually consider compare.

The main choices

.com — the default. When someone half-remembers a business name, they type .com. Global, neutral, trusted, and the one most likely to be taken. Renewal around £10–12/year. If it is available for your name, take it, even as a redirect.

.co.uk — the UK's commercial domain, run by Nominet. UK customers trust it and Google treats it as a UK location signal, which helps for local searches. Slightly cheaper than .com. The right primary domain for a business that trades in the UK; register the .com alongside if you can.

.uk — the shorter cousin, available since 2014. Fine, less recognised; people still add .co when typing.

.org — originally for non-profits; still reads that way. Use it for a charity, a community project or an open-source tool, not a shop.

.net — the historic fallback when .com was taken. Neutral but faintly second-choice; nobody types it by instinct.

.io — the tech startup TLD, from British Indian Ocean Territory. Reads as "software product". Renewal £30–45/year, and its future was uncertain after the territory's status changed in 2024–25 — ICANN has indicated it will continue, but it is a risk a .com does not carry.

.dev and .app — Google-run, technical, and HTTPS-only: browsers refuse to load them over plain HTTP, which is a feature. Good for developer tools and apps. £12–18/year.

.co — Colombia's TLD, marketed as "company". Common for startups that missed the .com; expect some visitors to type .com anyway.

.ai — Anguilla's TLD, now the AI industry's. £60–90/year, two-year minimum at many registrars. Only if you are actually an AI company.

Industry and city TLDs (.shop, .agency, .london, .tech) — fine for a brand that does its own marketing and will not rely on being guessed. Pricing varies wildly; some have cheap first years and £40+ renewals.

What search engines think

Google has said repeatedly that the TLD is not a ranking factor, with one exception: country-code TLDs (.co.uk, .de, .fr) geo-target the site to that country. That helps a UK business in UK results and slightly hurts it elsewhere. Generic TLDs (.com, .io, .dev) are neutral and can be geo-targeted in Search Console if needed. Keywords in the TLD (bestplumber.services) do nothing.

Restrictions to know about

• .co.uk and .uk require the registrant to be identifiable; a UK address is not required, but Nominet validates details.
• .eu requires an EU/EEA resident or company — UK businesses lost eligibility after Brexit.
• .dev/.app require HTTPS (a free certificate makes this a non-issue).
• Some country TLDs (.ca, .au, .fr) require local presence.

A simple rule

1. UK business selling mainly to UK customers: .co.uk as primary, .com redirecting to it if available.
2. Anything international, or ambiguous: .com.
3. Software product or developer tool: .com if you can; otherwise .dev, .app or .io in that order of renewal cost and stability.
4. Non-profit: .org.
5. Everything else: only if the brand is strong enough that nobody will need to guess the address.

Whatever you choose, register the obvious alternative (.com↔.co.uk) and redirect it, and read how to choose a domain name before settling on the part before the dot.

Renewal prices are the real cost

A first-year discount of £1 is marketing; check the renewal price before registering, and check whether the registrar charges for WHOIS privacy and DNS (both should be free). A .io at £45/year over ten years is £450 against a .co.uk's £80. Register for multiple years and set auto-renew — what happens when a domain expires is not a story with a happy ending.