GitHub Pages allows users to create and publish websites for their projects.
GitHub Pages feature has supported custom domains since 2009, and sites hosted on github.io subdomains have enjoyed HTTPS since 2016. But starting May 1, 2018, custom domains on GitHub Pages are also benefiting from this encrypted protocol.
HTTPS encrypts traffic between the website's servers and the visitors browsers. This is recognizable as the lock icon on browsers' address bar.
And GitHub in allowing custom domains using HTTPS means that it's delivering more than a million GitHub Pages websites over the encrypted protocol.
"We have partnered with the certificate authority Let’s Encrypt on this project," said GitHub's Parker Moore on a blog post. "As supporters of Let’s Encrypt’s mission to make the web more secure for everyone, we’ve officially become Silver-level sponsors of the initiative."
For custom domains on GitHub Pages to use HTTPS, actions may be required.
If users are using A records, they need to update their site's DNS records with new IP addresses.
And once they've updated the DNS records, they can confirm that their sites will load correctly over HTTPS. Optionally, they can "Enforce HTTPS" for their domain through their repository’s settings, ensuring users who request their site using HTTP are upgraded to HTTPS.
But if users are using CNAME or ALIAS records for their custom domain, nothing should be done as their site should be accessible over HTTPS. Users can still optionally enforce HTTPS through their repository’s settings.
The advantage of GitHub Pages users in using HTTPS is not only limited to encryption and security.
GitHub said that the IP addresses used for HTTPS "also places your site behind a content delivery network (CDN), allowing us to serve your site from data centers around the world at fast speeds, and offering additional protection against DDoS attacks."
Initially, previous IP addresses remain available for a transition period, but GitHub recommends that all GitHub Pages users to migrate to the new IP addresses to gain these benefits.
HTTPS is available for all GitHub Pages sites.