Domain availability checker.

Check whether a domain is available across popular extensions in one go — find the name before you build the brand.

Runs in your browser
Nothing is uploaded
Free — no sign-up

Find a domain

Name

Just the name — we add the extensions.

Extensions

Availability

Enter a name and pick the extensions to check across them at once.

Availability comes from live registry (RDAP) data. Register the name you want at any registrar — premium names may carry special pricing.

Good to know.

A domain availability checker tells you whether a domain name is registered or free across multiple extensions at once, using live registry (RDAP) data. This free tool checks .com, .co, .io, .app, and more in a single search.

Check the whole shortlist at once

Enter a name and we check availability across .com, .co, .io, .app and more in one pass, using live registry (RDAP) data — so you find an open name before you fall for a taken one.

Authoritative, not a guess

RDAP is the registries' structured WHOIS successor, so an "available" result reflects the actual registry, not a cached guess. Register through any registrar you like.

How to check domain availability

Enter a name. Type the name you want — we add the extensions.
Pick extensions. Select .com, .co, .io, .app, and any others.
Run the check. Check availability across all of them at once.
See the results. Find which extensions are still available.

Frequently asked

How accurate is the availability check?

It queries RDAP, the registries' authoritative data, so it's accurate at the moment you check. Premium or reserved names can still carry special pricing at the registrar.

Does checking a domain here register it?

No — this only checks availability. To register, take the name to a domain registrar. Nothing you type is stored.

Why are some extensions skipped?

We check the most common extensions for startups and businesses. A few niche TLDs don't expose public RDAP and are skipped rather than guessed.

Builder

Found the domain? Now give it a home.

A registered domain is just a name until something answers. Point it at sparx Builder and a Let’s Encrypt cert is provisioned automatically — a real, hosted, CDN-cached site on your domain, no DNS service or upcharge.

Explore Builder

What you get with sparx Builder.

The website module. Pick a theme, edit blocks in the browser, point your domain. SSL and the global CDN are handled for you. The same builder serves a one-page portfolio, a 40-post blog, or a 50,000-SKU catalog.

Theme-first.

Start from a polished theme, change the parts that matter, publish. Want full control? Build a custom frontend against the same API — coding optional, never required.

Block editor.

Drag, drop, edit in the browser. Every block is responsive and accessible by default — clean markup, no mystery wrappers, no shadow DOM.

Custom domain + SSL.

Point your DNS and your certificate provisions itself. No separate DNS service, no certificate to renew, no upcharge.

Builder is one module on the sparx platform — activate it alongside storefront, CRM, CMS, email, and B2B on one data layer and one bill. Only pay for what you run.

Explore the platform See pricing

More free tools.

Every sparx tool runs entirely in your browser — free, no account, nothing uploaded.