Dries Buytaert

Explanation

Identifies the software used by the origin server to handle the request (e.g. Apache, Nginx, Cloudflare).
Warning The server header exposes a specific version number (1.20.1). This makes it easier for attackers to find known vulnerabilities for that version. Remove or suppress the version number.

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.

The type of the message body, specified as a MIME type.

The size of the message body, in bytes.

X-Frame-Options prevents this URL from being embedded in an iframe. This protects against clickjacking attacks.
Notice sameorigin means that this page can be displayed in an iframe, but only on the current origin. It can't be displayed on another domain. Consider setting this to deny for added security.

Warning Caches must revalidate with the origin server before serving the page. If the page is something everybody can access, this behavior is not desired.
Notice Pragma is an HTTP/1.0 header. In HTTP/1.1, Pragma is deprecated and superseded by the Cache-Control header. Remove Pragma to save bandwidth and processing power.

Warning no-store means the response may not be stored in any cache, including the browser's cache.
Notice Using Pragma: no-cache without Cache-Control: no-cache is not recommended. Pragma is a legacy HTTP/1.0 directive. Use Cache-Control instead.

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.
includesubdomains instructs the browser that all subdomains are HTTPS-only as well.
preload recommends the domain for inclusion in browsers' preload lists. If accepted, the domain would get hardcoded into browsers as HTTPS-only.

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 an X-Content-Type-Options: nosniff header to prevent browsers from MIME type sniffing. Without it, browsers may interpret files as a different content type than intended, which can lead to security vulnerabilities.

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