Dries Buytaert

Explanation

Some of the software used to generate or serve this page.
Warning Sharing too many details about a server or web application makes it easier for hackers to target a website. Avoid specific version numbers such as 8.1.31, especially when running software that is end-of-life and/or has known security bugs. Consider removing this header. At a miminum, remove any version number.

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.

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

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.
Notice Varying on user-agent can lead to low cache efficiency due to the high number of unique user agents. Only use this if you're serving significantly different content based on user agent.

rel="preconnect" informs the browser that the page intends to establish a connection to the specified server. To reduce latency and optimize performance, the browser is encouraged to establish an HTTP connection as soon as possible. Preconnecting is used when the hostname is known, but the exact URL not yet.

rel="https://api.w.org/" is where you can learn more about WordPress' REST API. Applications can interact with this WordPress site by sending and receiving JSON objects.

Specifies a link that might be of interest to the browser.

rel="shortlink" specifies a shorter URL for the current page, to be used in space constrained interfaces and/or for manual entry.

The Content Security Policy (CSP) header helps prevent cross-site scripting (XSS), clickjacking, and other code injection attacks by specifying which dynamic resources are allowed to load.
upgrade-insecure-requests instructs browsers to replace insecure URLs (HTTP) with secure URLs (HTTPS).

A unique identifier that changes every time a page at a given URL changes. It acts as a fingerprint. A cache can compare Etag values to see if the page has changed and became stale. For example, a browsers will send the ETag value of a cached page in an If-None-Match header. The web server compares the ETag value sent by the browser with the ETag value of the current version of the page. If both values are the same, the web server sends back a 304 Not Modified status and no body.

The page was served from LiteSpeed's cache.

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.

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

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 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.