Dries Buytaert

Explanation

Used by the server to advertise its support of partial HTTP requests. The browser can ask for a range or subset of the response body. It's a feature that allows a browser to resume an interrupted download. bytes is the only range unit currently supported. none means that the server does not support range requests.

The time in seconds that the page has been in the shared proxy cache. The maximum age is set by max-age or s-maxage in the Cache-Control header.

The date and time at which the request was made. A browser uses it for age calculations rather than using its own internal date and time; e.g. when comparing against Max-Age or Expires.

Fastly's shield and edge servers that were queried for the request.

The page was not served from Fastly's cache. This site is a customer of Fastly's origin shielding feature for improved reliability.

The number of times this page has been served from the Varnish cache. Higher numbers are better.

The Vary header specifies a list of headers that must be considered when caching responses. For a cached response to be used, these headers must match between the cached response and the new request. This ensures that the appropriate version of a resource is served based on factors like language, encoding, or device type.

The Strict-Transport-Security header (HSTS) instructs browsers to only use HTTPS for future connections to this domain, enhancing security by preventing downgrade attacks and cookie hijacking.
max-age specifies the time, in seconds, that the browser should remember to use HTTPS only for this domain.
Notice For optimal security, consider increasing max-age to at least 31,536,000 seconds (1 year), especially if you're considering preloading.

The size of the message body, in bytes.

missing Add a Content-Security-Policy header. The Content-Security-Policy header helps browsers prevent cross site scripting (XSS) and data injection attacks.

missing Add a Referrer-Policy header. When a visitor navigates from one page to another, browsers often pass along referrer information. The Referrer-Policy header controls how much referrer information a browser can share. This is important to configure when private information is embedded in the path or query string and passed onto an external destination.

missing Add a Permissions-Policy header. Restrict access to device features like the camera, microphone, location, accelerometer and much more.

missing Add a Cross-Origin-Embedder-Policy to specify how this page can be loaded by cross-origin resources.

missing Add a Cross-Origin-Opener-Policy header to opt-in into better browser isolation.

missing Add a Cross-Origin-Resource-Policy header to specify who can load this page.

missing Add a X-Frame-Options header. The X-Frame-Options header prevents this URL from being embedded in an iframe. This protects against clickjacking attacks. Alternatively, set a Content-Security-Policy header with a frame-ancestor directive.

missing Add a X-Permitted-Cross-Domain-Policies header to prevent Flash, Adobe Reader and other clients from sharing data across domains.