Millions of people rely on GitHub Pages to host their websites and millions more visit these websites every day. To better protect traffic to GitHub Pages sites, as well as to encourage the broader adoption of HTTPS across the internet, GitHub Pages now officially1 supports HTTPS for all
<username>.github.io sites. HTTPS provides a layer of encryption that prevents others from snooping on or tampering with traffic to your Pages site.
You can now visit
*.github.io sites using HTTPS and configure HTTPS enforcement for your site. With HTTPS enforcement enabled, any HTTP requests to your
github.io site will be transparently redirected to HTTPS.
Starting next Wednesday (June 15, 2016, 12pm PDT), HTTPS enforcement will be required for all new GitHub Pages sites. To enable HTTPS enforcement for your existing
*.github.io site, visit the settings page for your site’s repository. Check out the Pages HTTPS documentation for more information.
1 You have been able to request Pages sites over HTTPS for some time, but we refrained from officially supporting it because the traffic from our CDN to our servers wasn’t encrypted until now.