People with admin permissions for a repository can configure a custom domain for a site.

About custom domain configuration

Make sure you add your custom domain to your site before configuring your custom domain with your DNS provider. Configuring your custom domain with your DNS provider without adding your custom domain to could result in someone else being able to host a site on one of your subdomains.

The dig command, which can be used to verify correct configuration of DNS records, is not included in Windows. To verify that your DNS records are configured correctly, you can use the Resolve-DnsName PowerShell command or install BIND.

Note: DNS changes can take up to 24 hours to propagate.

Configuring an apex domain

To set up an apex domain, such as example.com, you must configure a custom domain in your repository settings and at least one ALIAS, ANAME, or A record with your DNS provider.

1. Under "Custom domain", type your custom domain, then click Save. If you are publishing your site from a branch, this will create a commit that adds a CNAME file directly to the root of your source branch. If you are publishing your site with a custom workflow, no CNAME file is created, so you need to create one manually (containing only a line of text with your custom domain). For more information about your publishing source, see "AUTOTITLE."

2. Navigate to your DNS provider and create either an ALIAS, ANAME, or A record. You can also create AAAA records for IPv6 support. If you're implementing IPv6 support, we highly recommend using an A record in addition to your AAAA record, due to slow adoption of IPv6 globally.

   • To create an ALIAS or ANAME record, point your apex domain to the default domain for your site.

   • To create A records, point your apex domain to the IP addresses for .

     185.199.108.153
     185.199.109.153
     185.199.110.153
     185.199.111.153

   • To create AAAA records, point your apex domain to the IP addresses for .

     2606:50c0:8000::153
     2606:50c0:8001::153
     2606:50c0:8002::153
     2606:50c0:8003::153

3. To confirm that your DNS record configured correctly, use the dig command, replacing EXAMPLE.COM with your apex domain. Confirm that the results match the IP addresses for above.

   • For A records:

     $ dig EXAMPLE.COM +noall +answer -t A
     > EXAMPLE.COM    3600    IN A     185.199.108.153
     > EXAMPLE.COM    3600    IN A     185.199.109.153
     > EXAMPLE.COM    3600    IN A     185.199.110.153
     > EXAMPLE.COM    3600    IN A     185.199.111.153

   • For AAAA records:

     $ dig EXAMPLE.COM +noall +answer -t AAAA
     > EXAMPLE.COM     3600    IN AAAA     2606:50c0:8000::153
     > EXAMPLE.COM     3600    IN AAAA     2606:50c0:8001::153
     > EXAMPLE.COM     3600    IN AAAA     2606:50c0:8002::153
     > EXAMPLE.COM     3600    IN AAAA     2606:50c0:8003::153

     Remember to also check your A record.

Configuring an apex domain and the www subdomain variant

Note: Setting up a www subdomain alongside an apex domain is recommended for HTTPS secured websites.

For more information, see "Configuring a subdomain."

Navigate to your DNS provider and create a CNAME record for the www subdomain that points to your default domain. For example, if your site is located at <user>.github.io, you should create a CNAME record that points www.example.com to <user>.github.io Similarly, for an organization site located at <organization>.github.io, you should create a CNAME record that points www.example.com to <organization>.github.io. Ensure that the CNAME record points directly to <user>.github.io or <organization>.github.io without including the repository name.

Configuring a subdomain

To set up a www or custom subdomain, such as www.example.com or blog.example.com, you must add your domain in the repository settings. After that, configure a CNAME record with your DNS provider.

1. Under "Custom domain", type your custom domain, then click Save. If you are publishing your site from a branch, this will create a commit that adds a CNAME file directly to the root of your source branch. If you are publishing your site with a custom workflow, no CNAME file is created, so you need to create one manually (containing only a line of text with your custom domain). For more information about your publishing source, see "AUTOTITLE."

   Note: If your custom domain is an internationalized domain name, you must enter the Punycode encoded version.

   For more information on Punycodes, see Internationalized domain name.

2. Navigate to your DNS provider and create a CNAME record that points your subdomain to the default domain for your site. For example, if you want to use the subdomain www.example.com for your user site, create a CNAME record that points www.example.com to <user>.github.io. If you want to use the subdomain another.example.com for your organization site, create a CNAME record that points another.example.com to <organization>.github.io. The CNAME record should always point to <user>.github.io or <organization>.github.io, excluding the repository name.

3. To confirm that your DNS record configured correctly, use the dig command, replacing WWW.EXAMPLE.COM with your subdomain.

   $ dig WWW.EXAMPLE.COM +nostats +nocomments +nocmd
   > ;WWW.EXAMPLE.COM.                    IN      A
   > WWW.EXAMPLE.COM.             3592    IN      CNAME   YOUR-USERNAME.github.io.
   > YOUR-USERNAME.github.io.      43192   IN      CNAME   GITHUB-PAGES-SERVER .
   > GITHUB-PAGES-SERVER .         22      IN      A       192.0.2.1

   Note: If you point your custom subdomain to your apex domain, you will encounter issues with enforcing HTTPS to your website, and you may encounter issues where your subdomain does not reach your site at all.

DNS records for your custom domain

If you are familiar with the process of configuring your domain for a site, you can use the table below to find the DNS values for your specific scenario and the DNS record types that your DNS provider supports. For more information, including how to configure your site on and how to verify the configuration using the dig command, refer to the sections above.

To configure an apex domain, you only need to pick a single DNS record type from the table below. To configure an apex domain and www subdomain (for example, example.com and www.example.com), configure the apex domain and then the subdomain. For more information, see "Configuring an apex domain and the www subdomain variant."

Scenario	DNS record type	DNS record name	DNS record value(s)
Apex domain (example.com)	A	@	185.199.108.153 185.199.109.153 185.199.110.153 185.199.111.153
Apex domain (example.com)	AAAA	@	2606:50c0:8000::153 2606:50c0:8001::153 2606:50c0:8002::153 2606:50c0:8003::153
Apex domain (example.com)	ALIAS or ANAME	@	USERNAME.github.io or ORGANIZATION.github.io
Subdomain (ww​w.example.com, blog.example.com)	CNAME	SUBDOMAIN	USERNAME.github.io or ORGANIZATION.github.io

Removing a custom domain

If you get an error about a custom domain being taken, you may need to remove the custom domain from another repository.

1. Under "Custom domain," click Remove.

   ![Screenshot of a settings box to save or remove a custom domain on . To the right of a text box reading "example.com" is a button labeled "Remove" in red type.]

Securing your custom domain

For more information, see "AUTOTITLE."

Further reading

• "AUTOTITLE"