Apache:HSTS Header

<VirtualHost *:443>
    ServerAdmin support@example.com
    ServerName www.example.com
    SSLEngine on
    SSLCertificateFile /path/to/www.example.com.cert
    SSLCertificateKeyFile /path/to/www.example.com.key
    […]
    Header always set Strict-Transport-Security "max-age=31536000 ; includeSubdomains; preload"
    DocumentRoot /var/www/
</VirtualHost>

Source

• matrixpost.net