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About custom domains and GitHub Pages

GitHub Pages supports using custom domains, or changing the root of your site's URL from the default, like octocat.github.io, to any domain you own.

GitHub Pagesは、GitHub Free及びOrganizationのGitHub Freeのパブリックリポジトリ、GitHub Pro、GitHub Team、GitHub Enterprise Cloud、GitHub Enterprise Serverのパブリック及びプライベートリポジトリで利用できます。 詳細については、「GitHub's products」を参照してください。

Supported custom domains

GitHub Pages works with two types of domains: subdomains and apex domains. For a list of unsupported custom domains, see "Troubleshooting custom domains and GitHub Pages."

Supported custom domain typeExample
www subdomainwww.example.com
Custom subdomainblog.example.com
Apex domainexample.com

You can set up either or both of apex and www subdomain configurations for your site. For more information on apex domains, see "Using an apex domain for your GitHub Pages site."

We recommend always using a www subdomain, even if you also use an apex domain. When you create a new site with an apex domain, we automatically attempt to secure the www subdomain for use when serving your site's content, but you need to make the DNS changes to use the www subdomain. If you configure a www subdomain, we automatically attempt to secure the associated apex domain. For more information, see "Managing a custom domain for your GitHub Pages site."

After you configure a custom domain for a user or organization site, the custom domain will replace the <user>.github.io or <organization>.github.io portion of the URL for any project sites owned by the account that do not have a custom domain configured. For example, if the custom domain for your user site is www.octocat.com, and you have a project site with no custom domain configured that is published from a repository called octo-project, the GitHub Pages site for that repository will be available at www.octocat.com/octo-project. For more information about each type of site and handling custom domains, see "Types of GitHub Pages sites."

Using a subdomain for your GitHub Pages site

A subdomain is the part of a URL before the root domain. You can configure your subdomain as www or as a distinct section of your site, like blog.example.com.

Subdomains are configured with a CNAME record through your DNS provider. For more information, see "Managing a custom domain for your GitHub Pages site."

www subdomains

A www subdomain is the most commonly used type of subdomain. For example, www.example.com includes a www subdomain.

www subdomains are the most stable type of custom domain because www subdomains are not affected by changes to the IP addresses of GitHub Enterprise Cloud's servers.

Custom subdomains

A custom subdomain is a type of subdomain that doesn't use the standard www variant. Custom subdomains are mostly used when you want two distinct sections of your site. For example, you can create a site called blog.example.com and customize that section independently from www.example.com.

Using an apex domain for your GitHub Pages site

An apex domain is a custom domain that does not contain a subdomain, such as example.com. Apex domains are also known as base, bare, naked, root apex, or zone apex domains.

An apex domain is configured with an A, ALIAS, or ANAME record through your DNS provider. For more information, see "Managing a custom domain for your GitHub Pages site."

カスタム ドメインとして Apex ドメインを使用している場合は、www サブドメインも設定することをお勧めします。 DNSプロバイダを通じて各ドメインの種類のための正しいレコードを設定しているなら、GitHub Pagesは自動的にドメイン間のリダイレクトを生成します。 たとえば、www.example.com をご自分のサイトのカスタム ドメインとして構成し、GitHub Pages DNS レコードを Apex と www のドメインに設定している場合、example.comwww.example.com にリダイレクトされます。 自動リダイレクトは www サブドメインにのみ適用されることに注意してください。 自動リダイレクトは、blog などのその他のサブドメインには適用されません。 For more information, see "Managing a custom domain for your GitHub Pages site."

Securing the custom domain for your GitHub Pages site

GitHub Pages サイトが無効になっているが、カスタム ドメインが設定されている場合、ドメインの乗っ取りのリスクがあります。 サイトが無効な間に、DNS プロバイダでカスタムドメインを設定していると、サブドメインのいずれかで誰かにサイトをホストされてしまう恐れがあります。

カスタム ドメインを確認すると、他の GitHub ユーザーが自分のリポジトリでそのドメインを使用できなくなります。 ドメインが確認されておらず、GitHub Pages サイトが無効になっている場合は、DNS プロバイダーで DNS レコードを直ちに更新または削除する必要があります。 For more information, see "Verifying your custom domain for GitHub Pages" and "Managing a custom domain for your GitHub Pages site."

There are a couple of reasons your site might be automatically disabled.

  • If you downgrade from GitHub Pro to GitHub Free, any GitHub Pages sites that are currently published from private repositories in your account will be unpublished. For more information, see "Downgrading your GitHub billing plan."
  • If you transfer a private repository to a personal account that is using GitHub Free, the repository will lose access to the GitHub Pages feature, and the currently published GitHub Pages site will be unpublished. For more information, see "Transferring a repository."

Further reading