HTTP Headers: three.co.uk

Accept-Ranges
Access-Control-Allow-Headers
Access-Control-Allow-Methods
Cache-Control
ClientIPHeader
Connection
Content-Disposition
Content-Encoding
Content-Length
Content-Security-Policy
Content-Type
Date
ETag
Last-Modified
Pragma
RemoteIPHeader
Server
Set-Cookie
Strict-Transport-Security
TestIPHeader
Vary
X-Content-Type-Options
X-Frame-Options
X-XSS-Protection

Strict-Transport-Security (HSTS) forces browsers to use HTTPS. Content-Security-Policy (CSP) prevents XSS attacks by controlling which resources can load. X-Content-Type-Options stops MIME-type sniffing. X-Frame-Options blocks clickjacking by preventing iframe embedding.

three.co.uk's security score of 40/100 reflects how many of these protective headers are configured. Higher scores indicate better defense against common web attacks.