Put a ChatGPT Site on a domain you own.

What OpenAI documents today

Creating a Site requires a paid ChatGPT plan; OpenAI's help center lists every plan except Free and Go, and Sites reached the UK, the EEA, and Switzerland on 20 July 2026 after a launch exclusion. Custom domains were added to the documentation shortly after the July 2026 launch: you can connect an apex domain or a subdomain you already own by updating DNS records, "where available", and not for sites owned by an Enterprise workspace at launch. In our own hands-on test on 22 August 2026, a personal account's site settings offered the custom-domain option, alongside analytics and environment variables.

Without a custom domain, the site serves from OpenAI's namespace. Launch-era sites published at {name}.openai.chatgpt.site; new sites now publish at a user-namespaced address like {site}.{account}.chatgpt.site. Updates redeploy to the same URL, which is genuine replace-in-place and worth crediting.

The DNS reality

Connecting a domain means updating records at your registrar; the domain stays registered where it is, and nothing transfers to OpenAI. Beyond that, the public documentation is thinner than you might expect: it stops short of naming the record types, describing a verification step, explaining certificate handling, or stating how many domains a plan gets. Those answers live inside the connect flow rather than on a public page, so the honest planning advice is: run the flow in your own workspace before you promise a client a date, and allow for ordinary DNS propagation on top.

The "where available" hedge is doing real work. The docs say availability can depend on your plan, region, and workspace settings, and Enterprise-owned sites are excluded at launch. Until the option appears in your own site settings, treat it as unconfirmed for your account.

One adjacent, tested fact: renaming a Site's ChatGPT-hosted address returns an HTTP 307 redirect from the old address, carrying deep routes and query strings intact. Old links keep working for humans, but a 307 is temporary, so search engines are never told a move is permanent. If an address matters to you long-term, put the domain you own in front early rather than renaming later.

What a custom domain does not change

The domain changes the address, not the audience. The documented viewing options are the same with or without one: a Site is public to anyone on the internet, or restricted to signed-in accounts in your workspace. On a personal plan that reduces to two modes, "Only you" and "Anyone with the link". There is no passcode, no email-domain gate a viewer can pass without an account, and no documented expiry. So report.yourstudio.com on a ChatGPT Site is either open to the whole internet or closed to everyone outside your workspace; there is no setting in between for one named client.

The publishing side is also unchanged: Sites is created and managed in conversation, with no documented API, MCP surface, or CLI, and no documented export. And built-in analytics (visitors and page views) is not available for Enterprise-owned sites. None of this is a flaw if the site is a team tool or a public microsite; it only bites when the page is a private deliverable.

Client work on your own domain, with a gate

This section describes Stacktree, our product, so read it as us explaining where we fit. The case Sites does not cover is the common one in client work: a page at reports.yourstudio.com that one named person outside your company can open, with no account, and that nobody else can find. The route:

1. Get the deliverable as a single HTML file. There is no documented Site export, so do not try to move the Site. Ask ChatGPT for a static, single-file HTML rendering of the page, or have an agent produce it directly.
2. Publish it to Stacktree. Drag and drop, or over MCP from Claude, Codex, or Cursor. The URL is unguessable and never indexed by default.
3. Gate it. Add a passcode (on every plan, including free) or restrict viewing to the client's company email domain (paid). The client types a code or their work email; no account exists to create.
4. Bind your domain. Add the hostname, create the CNAME and TXT records it gives you, and SSL provisions automatically through Cloudflare for SaaS. Solo ($19 per month) includes 1 domain, Studio ($79) 10, Firm 25, and a domain re-binds to any page whenever the next engagement starts.

Because a Stacktree page updates in place, revising the deliverable never changes the URL under the domain. And if the client gets more than one deliverable, bind the hostname to a client space instead of a single page: acme.yourstudio.com then serves everything filed for that client behind one passcode. The full DNS detail, including claiming a parent domain once with a wildcard CNAME, is on the custom domains page.

To be fair about the trade: Stacktree hosts static HTML only, with no server logic or database. If what you built is a live application and the audience is the open internet or your own team, ChatGPT Sites now handles the domain natively and there is no reason to leave. The route above exists for the audience Sites does not serve: gated, account-free, on your domain.