Who owns my website — me or the developer who built it?

The short answer
Usually you, but only if it is in writing. In most arrangements you own the domain, the content and the design you paid to have made. The developer may keep the rights to reusable code they wrote before your project. Get three things confirmed on paper: the domain registered in your name, a copy of the source files, and the right to keep using the design if you part ways.
On this page
Ownership is not one question
"Who owns the website" sounds like a single question with a single answer. It is really three, and they get decided separately — often without anyone discussing them.
1. The domain
This is the one that matters most and gets checked least.
Whoever is listed as the registrant owns the domain, regardless of who pays for it. If your developer registered it on your behalf, it may be in their name or their agency's — not out of malice, just because it was faster at the time.
Check it now, while nothing is wrong. Look up your domain on any WHOIS service, or ask your developer to send you the registrar login. If the registrant is not you or your company, ask for a transfer. It is a routine request and takes a few days.
2. The source files
The site running on a server is the output. The source files are what it was built from, and you need them to move anywhere or change anything meaningfully.
In most freelance and agency arrangements, work you commissioned and paid for belongs to you. But "most" is doing real work in that sentence. Some contracts license the site to you rather than transferring it, which is a different thing entirely — you are renting.
Ask for a copy of the source files while the relationship is good. A developer who is happy to hand them over is telling you something useful. So is one who is not.
3. The design and the code underneath it
Here the honest answer has some nuance in it.
The design made specifically for you is normally yours. But a developer who has built forty restaurant sites has almost certainly reused components across them, and they usually retain the rights to that underlying work. This is standard and reasonable — you commissioned a website, not the exclusive rights to every technique used to build one.
What you want is a licence that says you can keep using and modifying your site indefinitely, including if you stop working together. That single sentence prevents most disputes.
What to do about it
You do not need a lawyer for this. You need one email:
Could you confirm in writing that the domain is registered to me, that I have a copy of the source files, and that I can continue using and modifying the site if we stop working together?
Send it while everything is fine. The answer costs nothing to get now and can be expensive to establish later.
If you have already lost touch with the developer
You still have more options than it feels like. The domain can usually be recovered through the registrar with proof of the business, and a site that is live can be preserved even without the original source. That is its own question, and it has its own answer.
What a good arrangement looks like
Worth knowing what you are aiming at, because "you own it" is a phrase everyone uses and it means different things.
The three answers you want, in writing:
- The domain is registered to your business, with you as the registrant, not your developer
- You have the source files, and getting them again does not depend on anyone's cooperation
- You can keep using and modifying the site whether or not you keep working together
Some platforms cannot give you the second one at all. A site built inside a closed builder has no source files to hand over — that is not the builder being difficult, it is what the product is. If that matters to you, it has to be settled before you build, not after.
This is the specific reason Helm registers the domain in the client's name and gives them the code: the answer to all three questions above is yes by default, and it is yes on the day you decide to leave rather than only on the day you sign up. A platform that makes leaving easy has to earn staying on its own merits, which is the arrangement we would rather be in anyway.