Dries Buytaert

HTTP Headers Analyzer

1 / 10
WordPress → LiteSpeed → CloudFlare → Browser
10 missing headers, 5 warnings, 5 notices
This site is paying for a CDN but not caching anything for anonymous visitors. It's like lighting money on fire! 💵 🔥
sat, 25 mar 2023 05:38:56 gmt
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 compairing against Max-Age or Expires.
text/html; charset=utf-8
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.
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 7.4.33, 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.
DNS requests are very small in terms of bandwidth, but latency can be quite high. Prefetching DNS results can significantly improve page load performance.
Notice This feature is non-standard and is not on a standards track. Not supported by all browsers.
thu, 19 nov 1981 08:52:00 gmt
This Expires date is in the past: the page is considered stale and will be removed from all caches.
missing 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.
PS: November 19th is my birthday! 🎂
no-store, no-cache, must-revalidate
no-cache means the response can be stored by any cache, but that the stored page must be validated with the origin before it can be served. If the origin confirms that the page has not changed, downloading of the body can be skipped.
Warning no-cache will cause a roundtrip to the origin web server for every request. Consider using public to avoid roundtrips and improve caching.
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.
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.
The page was served from LiteSpeed's cache.
Some of the software used to generate or serve this page.
Warning dynamic means that Cloudflare did not cache the HTML page. It's equivalent to a cache miss. Cloudflare's dynamic cache setting only caches static assets like images, videos, CSS files, JavaScript files and more. HTML pages will never be cached and will always be requested from the origin web server. This can be expensive for dynamically generated HTML. To cache HTML files in Cloudflare, change the 'Cache level' setting from dynamic to everything.
The Report-To header instructs the browser where to send "Network Error Logging" (NEL) reports to.
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.
The "Network Error Logging" (NEL) header is used to configure network request logging; enables websites and applications to receive reports about failed network fetches from supporting browsers.
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.
success_fraction defines the sampling rate that should be applied to reports about successful network requests. Its value must be a number between 0.0 and 1.0: 0 means no successful requests should be reported, and 1 means that every successful request should be reported.
Some of the software used to generate or serve this page.
A unique request ID generated by Cloudflare. Cloudflare's customer support can use this identifier to trace a request through its network.
h3=":443"; ma=86400, h3-29=":443"; ma=86400
Used to promote alternative services through which the same resource can be retrieved.
h3 stands for HTTP/3. The number after the dash indicates the draft; e.g. h3-27 would be draft 27 of the HTTP/3 protocol.
ma is the number of seconds the alternative service is considered fresh.
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-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.

Questions or feedback? Email dries@buytaert.net.