Custom Domains

Custom domains allow you to serve your documentation from your own domain. This is great for maintaining a consistent brand for your documentation and application.

By default, your documentation is served from a Read the Docs subdomain using the project’s slug:

  • <slug> for Read the Docs Community

  • <slug> for Read the Docs for Business.

For example if you import your project and it gets the slug example-docs, it will be served from

Adding a custom domain

To setup your custom domain, follow these steps:

  1. Go the Admin tab of your project.

  2. Click on Domains.

  3. Enter the domain where you want to serve the documentation from (e.g.

  4. Mark the Canonical option if you want use this domain as your canonical domain.

  5. Click on Add.

  6. At the top of the next page you’ll find the value of the DNS record that you need to point your domain to. For Read the Docs Community this is, and for Read the Docs for Business the record is in the form of <hash>


    For a subdomain like add a CNAME record, and for a root domain like use an ANAME or ALIAS record.

By default, we provide a validated SSL certificate for the domain, managed by Cloudflare. The SSL certificate issuance should happen within a few minutes, but might take up to one hour. See SSL certificate issue delays for more troubleshooting options.

As an example, our blog’s DNS record looks like this:

dig +short CNAME


We don’t support pointing subdomains or root domains to a project using A records. DNS A records require a static IP address and our IPs may change without notice.

Removing a custom domain

To remove a custom domain:

  1. Go the Admin tab of your project.

  2. Click on Domains.

  3. Click the Remove button next to the domain.

  4. Click Confirm on the confirmation page.


Once a domain is removed, your previous documentation domain is no longer served by Read the Docs, and any request for it will return a 404 Not Found!

Strict Transport Security (HSTS) and other custom headers

By default, we do not return a Strict Transport Security header (HSTS) for user custom domains. This is a conscious decision as it can be misconfigured in a not easily reversible way. For both Read the Docs Community and Read the Docs for Business, HSTS and other custom headers can be set upon request.

We always return the HSTS header with a max-age of at least one year for our own domains including *, *, and

Please contact Site Support if you want to add a custom header to your domain.

Multiple documentation sites as sub-folders of a domain

You may host multiple documentation repositories as sub-folders of a single domain. For example, and This is a way to boost the SEO of your website.

See Subprojects for more information.


SSL certificate issue delays

The status of your domain validation and certificate can always be seen on the details page for your domain under Admin > Domains > YOURDOMAIN.TLD (details).

Domains are usually validated and a certificate issued within minutes. However, if you setup the domain in Read the Docs without provisioning the necessary DNS changes and then update DNS hours or days later, this can cause a delay in validating because there is an exponential back-off in validation.


Loading the domain details in the Read the Docs dashboard and saving the domain again will force a revalidation.

The validation process period has ended

After you add a new custom domain, you have 30 days to complete the configuration. Once that period has ended, we will stop trying to validate your domain. If you still want to complete the configuration, go to your domain and click on Save to restart the process.

Migrating from GitBook

If your custom domain was previously used in GitBook, contact GitBook support (via live chat in their website) to remove the domain name from their DNS Zone in order for your domain name to work with Read the Docs, else it will always redirect to GitBook.