Dries Buytaert

Explanation

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.

A cookie that was sent from the server to the browser.
path= indicates the path that must exist in the requested URL for the browser to send the cookie.
Warning samesite=none instructs the browser to send the cookie to all cross-site requests, such as on requests to load images or frames from other sites. This enables third-party sites to log cookie data. This could lead to data leaks and cross-site request forgery attacks. To improve security, set to samesite=strict or samesite=lax.
secure instructs the browser to only send the cookie back when HTTPS requests are used, making it more resistant to man-in-the-middle attacks.

Defines the HTTP authentication methods and details that can be used to gain access to this page.

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.

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.

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.
max-age=0 with must-revalidate means caching is disabled and all requests must be validated with the origin server.
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.

Warning The page can't be cached by any shared caches such as Varnish or a CDN. If the page is something everybody can access, this behavior is not desired.
Notice Pragma is a HTTP/1.0 header. This request uses HTTP/1.1. In HTTP/1.1, Pragma is deprecated and superseded by the Cache-Control header. Remove Pragma to save bandwidth and processing power.

This Expires date is in the past: the page is considered stale and will be removed from all caches.
Notice Because there is a Cache-Control header with a max-age and/or s-maxage directive, the Expires header will be ignored. Consider removing Expires to save bandwidth and processing power.

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.

X-Frame-Options prevents this URL from being embedded in an iframe. This protects against clickjacking attacks.
deny means that this page can never be displayed in an iframe. It's the most secure option.

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.

This header is part of the Reporting API specification. They are used to configure the reporting of network errors and other issues to a specified endpoint.
The NEL (Network Error Logging) header configures the reporting of network errors.
report_to defines the reporting group that reports for this NEL policy will be sent to. The reporting group details are specified in the Report-To header.
max_age defines the number of seconds the browser should remember these settings. Prevents the browser from having to parse the JSON on each request.
include_subdomains is a boolean that enables or disables NEL reporting for subdomains of the origin.

This header is part of the Reporting API specification. They are used to configure the reporting of network errors and other issues to a specified endpoint.
The Report-To header specifies where reports should be sent.
group defines the reporting group. Groups allow reports to be grouped logically; e.g. there could be a group for network errors and a second group for browser feature deprecation reports.
max_age defines the number of seconds the browser should remember these settings. Prevents the browser from having to parse the JSON on each request.
endpoints defines one or more URLs where the reports need to be send to. Multiple URLs can be specified for failover and load-balancing. Endpoints can be assigned a weight to distribute load, with each endpoint receiving a specified fraction of the reporting traffic. Endpoints can also be assigned a priority to set up fallback collectors.
include_subdomains is a boolean that enables or disables NEL reporting for subdomains of the origin.

A unique identifier for the HTTP request. This can be useful for tracking a request through complex systems or for debugging purposes.

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.