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 (1.22.0). 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.

Specifies whether the network connection stays open after the current request. keep-alive specifies that the browser would like to keep the connection open, while close indicates that the browser wants to close the connection.

Lists the HTTP methods (e.g. GET, POST, DELETE) that the server supports for this URL. Typically included in 405 Method Not Allowed responses to tell the client which methods are valid.

Some of the software used to generate or serve this page.

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.

This header enables the browser's built-in XSS protection. However, it's considered legacy and modern browsers may ignore it.
1 enables the browser's cross-site scripting (XSS) filtering.
mode=block instructs the browser to block the response if a XSS attack is detected, instead of sanitizing the page.
Notice While this header provides some protection, it's recommended to use Content-Security-Policy instead, as it offers more comprehensive and flexible protection against XSS and other injection attacks.

The X-Content-Type-Options header, when set to nosniff, prevents MIME type sniffing. This enhances security by ensuring browsers respect the declared Content-Type of the response, mitigating MIME confusion attacks.
The value nosniff is correctly set, providing protection against MIME type sniffing attacks.

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 In HTTP/1.1, Pragma is deprecated and superseded by the Cache-Control header.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.

no-cache means the response can be stored by any cache, but the stored response must be validated with the origin server before each reuse. If the origin confirms that the response hasn't changed, downloading of the full response body can be skipped.
Warning no-cache will cause a revalidation request to the origin server for every use of the cached response. Consider using public with appropriate max-age to improve caching efficiency.
Warning no-store means the response may not be stored in any cache, including the browser's cache.
must-revalidate indicates that once a page becomes stale, both shared caches and browser caches must not use their stale copy without validating it with the origin server first.
Notice It does not make sense to set must-revalidate with no-store; when nothing is cached, there is nothing to revalidate.
Notice It does not make sense to set must-revalidate with no-cache; must-revalidate is implied.
Notice no-store is set, so it does not make sense to set no-cache as well.

This Expires date is in the past: the page is considered stale and will be removed from all caches.
Notice The Cache-Control header, introduced in HTTP/1.1, supersedes the Expires header. Use a Cache-Control header with a max-age directive instead of Expires. Cache-Control is more powerful, but also more efficient in that it avoids roundtrips to the origin server.

missing Add a Strict-Transport-Security header. The Strict-Transport-Security header or HSTS header is used to instruct browsers to only use HTTPS, instead of using HTTP. It helps enforce secure communication.

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