Dries Buytaert

HTTP Headers Analyzer

2 / 10
https://www.etsy.com
WordPress → Varnish → Fastly → Browser
9 missing headers, 3 warnings, 6 notices
The site is using a CDN, but the HTML page is not cached.
Header
Value
Explanation
content-type
text/html;charset=utf-8
The type of the message body, specified as a MIME type.
server
datadome
x-datadome
protected
accept-ch
sec-ch-ua,sec-ch-ua-mobile,sec-ch-ua-platform,sec-ch-ua-arch,sec-ch-ua-full-version-list,sec-ch-ua-model,sec-ch-device-memory
The Accept-CH header specifies HTTP Client Hints that the server requests from the client (typically a browser) to optimize content delivery.
  • sec-ch-ua: Requests a condensed version of the user agent string.
  • sec-ch-ua-mobile: Requests a boolean hint indicating if the client's device is mobile.
  • sec-ch-ua-platform: Requests the operating system platform of the client's device, such as Windows or MacOS.
  • sec-ch-ua-arch: Requests the client's device CPU architecture, such as ARM or x86.
  • sec-ch-ua-full-version-list: Requests a detailed list of version numbers for the client's browser and its significant components.
  • sec-ch-ua-model: Requests the model of the client's device.
charset
utf-8
cache-control
max-age=0, private, no-cache, no-store, must-revalidate
private means the response can only be stored by the browser's cache, but not by CDNs, proxies, or any other shared caches.
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.
Notice no-store is set, so it does not make sense to set private as well.
pragma
no-cache
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.
access-control-allow-credentials
true
Indicates whether a browser can expose the request's credentials, including cookies and authorization headers, to frontend JavaScript code.
access-control-expose-headers
x-dd-b, x-set-cookie
Specifies which headers can be exposed to the client in a CORS (Cross-Origin Resource Sharing) context.
access-control-allow-origin
*
Indicates whether a browser can share this resource with other code. * is a wildcard. It means the browser will allow code from any origin to access this resource.
x-datadome-cid
ahrlqaaaaama3ok7yiwpcgoanlhgtw==
x-dd-b
1
x-fastly-backend-reqs
196
accept-ranges
bytes
Used by the server to advertise its support of partial HTTP requests. The browser can ask for a range or subset of the response body. It's a feature that allows a browser to resume an interrupted download. bytes is the only range unit currently supported. none means that the server does not support range requests.
date
fri, 11 jul 2025 05:40:12 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 comparing against Max-Age or Expires.
via
1.1 varnish
The Via header tracks how a page is forwarded from proxy to proxy. Beware, not all proxies append themselves to the Via header.
x-served-by
cache-iad-kiad7000159-iad
Fastly's shield and edge servers that were queried for the request.
x-cache
miss
The page was not served from a cache.
x-cache-hits
0
The number of times this page has been served from the Varnish cache. Higher numbers are better.
x-timer
s1752212412.103861,vs0,ve4
Provides timing information about the journey of a request through Fastly's network. Format: s<timestamp>,vs<seconds>,ve<seconds>, where s is the start time of the request, ve stands for Varnish start and ve stands for Varnish end. The length of the trip is ve - vs milliseconds.
content-length
736
The size of the message body, in bytes.
strict-transport-security
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.
content-security-policy
missing Add a Content-Security-Policy header. The Content-Security-Policy header helps browsers prevent cross site scripting (XSS) and data injection attacks.
referrer-policy
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.
permissions-policy
missing Add a Permissions-Policy header. Restrict access to device features like the camera, microphone, location, accelerometer and much more.
cross-origin-embedder-policy
missing Add a Cross-Origin-Embedder-Policy to specify how this page can be loaded by cross-origin resources.
cross-origin-opener-policy
missing Add a Cross-Origin-Opener-Policy header to opt-in into better browser isolation.
cross-origin-resource-policy
missing Add a Cross-Origin-Resource-Policy header to specify who can load this page.
x-frame-options
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.
x-permitted-cross-domain-policies
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.