We just rolled out some big improvements to GitHub Pages. Now, when someone visits a Pages site, rather than GitHub serving the content directly, the page is served by a global Content Delivery Network, ensuring that the nearest physical server can serve up a cached page at blazingly fast speeds. As an added bonus, we can now protect your GitHub Pages site with the same kind of Denial of Service mitigation services used for GitHub.com.

If you are using a subdomain, custom subdomain, or an A record with GitHub Pages, you may need to make some changes.

Default User Domain – username.github.io

Default subdomains are automatically updated by our DNS, so we’ve got you covered.

Custom Subdomain (www.example.com) – with CNAME

If you are using a custom subdomain (like www.example.com), you should use a CNAME record pointed at username.github.io as described in our help article.

Apex domain (example.com) – with ALIAS or A

If you currently use an A record, you can tell if you need to move if your A record is pointed to or You can check using:

$ dig example.com
example.com.    7200  IN  A


$ dig example.com
example.com.    7200  IN  A

Some DNS providers (like DNSimple) allow you to use an ALIAS record to point your custom apex domain to username.github.io. If your DNS provider supports this configuration, it will allow us to provide the full benefits of our Content Delivery Network and Denial of Service protection to your Pages site.

If you switch to a subdomain or switch to a DNS provider that supports ALIAS records, you can take advantage of the Content Delivery Network and Denial of Service mitigation.

If you are using an apex domain (e.g. example.com) instead of a subdomain (e.g. www.example.com) and your DNS provider does not support ALIAS records, then your only option is to use A records for your DNS. This configuration will not give your Page the benefit our Content Delivery Network, but you will still be protected by our Denial of Service mitigation. Configure your A or ALIAS records as described in our help article.

Happy (and faster) publishing!