HTTP Headers Analyzer

8 / 10

https://dashd.netlify.app

Website → Netlify → Browser
0 missing headers, 1 warnings, 3 notices
JSON API

Header	Value	Explanation
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.
age	1	The time in seconds that the page has been in the shared proxy cache. The maximum age is set by `max-age` or `s-maxage` in the `Cache-Control` header.
cache-control	public,max-age=3600	`public` means the response may be stored by all caches, including browser caches, CDNs, and shared caches. `max-age` specifies the maximum amount of seconds a page is considered valid. The higher `max-age`, the longer a page can be cached.
cache-status	"netlify edge"; fwd=miss; fwd-status=200; stored	A standardized header (RFC 9211) for reporting cache status. Unlike vendor-specific headers like `X-Cache` or `CF-Cache-Status`, this is a structured header that can represent multiple cache layers (e.g. CDN and origin cache) in a single value.
content-encoding	br	Specifies how the resource is compressed. Not to be confused with `Transfer-Encoding` which specifies how the data is transferred. `br` means that the data is compressed with `brotli`. Warning Add a `Content-Length` header. The Content-Length header is required, unless the message is transported using chunked encoding. Without a `Content-Length` header some servers will respond with 400 (bad request) or terminate connections early.
content-security-policy	default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self'; font-src 'self'; connect-src 'self'; frame-src 'self'; object-src 'none'; upgrade-insecure-requests	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. `default-src` sets the default policy for fetching resources like JavaScript, images, CSS, fonts, AJAX requests, frames, HTML5 media. `script-src` specifies valid sources for JavaScript. This includes not only URLs loaded directly into `<script>` elements, but also things like inline script event handlers (onclick) and XSLT stylesheets which can trigger script execution. `object-src` defines what `<object>`, `<embed>` and `<applet>` elements are allowed to be loaded and executed. `style-src` defines what CSS stylesheets are allowed to be loaded. `img-src` defines what images and favicons can be loaded. `font-src` defines what fonts can be loaded using CSS's `@font-face`. `frame-src` defines what `<frame>` and `<iframe>` elements can be loaded. `upgrade-insecure-requests` instructs browsers to replace insecure URLs (HTTP) with secure URLs (HTTPS). Notice `unsafe-inline` in `style-src` allows inline styles. This is common and lower risk than inline scripts, but nonces or hashes provide stronger protection. Notice Consider adding `base-uri 'self'` or `base-uri 'none'` to prevent base tag injection, which can redirect relative URLs to an attacker-controlled domain.
content-type	text/html; charset=utf-8	The type of the message body, specified as a MIME type.
cross-origin-embedder-policy	require-corp	Controls whether this page can load resources (images, scripts, iframes) from other origins. When set, every cross-origin resource must explicitly opt in (via a `Cross-Origin-Resource-Policy` header or CORS) before this page can load it. This protects those other origins: by requiring their consent, the browser ensures their resources aren't exposed to Spectre-style timing attacks from this page. Setting this header (together with `Cross-Origin-Opener-Policy: same-origin`) is also required to enable powerful features like `SharedArrayBuffer` and high-resolution timers. `require-corp` means this page can only embed same-origin resources, or cross-origin resources that explicitly consent by sending a `Cross-Origin-Resource-Policy: cross-origin` header (or the equivalent CORS headers). Resources without that consent are blocked.
cross-origin-opener-policy	same-origin	Controls whether other pages can access this page's `window` object (and vice versa) when opened via `window.open()` or by navigating to a new page. Without this header, a malicious page could open your site and retain a reference to its `window`, enabling script-based attacks through the shared browsing context. Setting this to `same-origin` severs that link for cross-origin pages. Note: COOP governs top-level documents and popups, not iframes. Use `X-Frame-Options` or CSP `frame-ancestors` to control iframe embedding. `same-origin` isolates this page completely. Cross-origin pages that open this page (or are opened by it) will get `window.opener` set to `null` and cannot script each other. This is the strictest and most secure option.
cross-origin-resource-policy	same-origin	Controls which origins are allowed to load this resource (e.g. embed this image, load this script). This prevents other sites from hotlinking your resources and is how a resource signals its consent to be loaded by pages that use `Cross-Origin-Embedder-Policy`. `same-origin` means the resource can only be loaded by documents from the same origin.
date	fri, 13 nov 2026 09:42:45 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`.
etag	w/"f2afb23fd2d00b47349bbe560c836972-ssl"	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 has become stale. For example, a browser 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. This particular `ETag` value starts with `W/` which means that it is a weak identifier; while unlikely, multiple pages might have the same identifier. Weak identifiers are used because strong identifiers can be difficult and costly to generate.
permissions-policy	camera=(), microphone=(), geolocation=()	Controls which browser features and APIs (camera, microphone, geolocation, payment, USB, etc.) this page and its embedded iframes are allowed to use. Each feature is set to an allowlist of origins; an empty list `()` disables the feature entirely. This is a defense-in-depth measure: even if an attacker injects script via XSS, they cannot access the restricted APIs.
referrer-policy	strict-origin-when-cross-origin	When a visitor navigates from one page to another page, browsers often pass along referrer information. The `Referrer-Policy` header controls how much referrer information a browser can share. This is important because private information can be embedded in the path or query string. `strict-origin-when-cross-origin` means that the full URL (protocol, host, port, path and query string) is shared for same-origin requests. For cross-origin requests, only the origin (protocol, host, and port) is shared, and only when the protocol security level stays the same or improves (HTTP → HTTP, HTTPS → HTTPS). For cross-origin requests where the protocol downgrades (HTTPS → HTTP), nothing is shared.
server	netlify	Identifies the software used by the origin server to handle the request (e.g. Apache, Nginx, Cloudflare). Notice Consider removing or minimizing the `Server` header. Even without a version number, it reveals the server software, which aids reconnaissance.
strict-transport-security	max-age=31536000; includesubdomains; preload	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. `preload` recommends the domain for inclusion in browsers' preload lists. If accepted, the domain would get hardcoded into browsers as HTTPS-only.
vary	accept-encoding	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.
x-content-type-options	nosniff	The `X-Content-Type-Options` header prevents browsers from guessing a response's content type. Without it, browsers may interpret files differently than intended, which can lead to security vulnerabilities. The value `nosniff` is correctly set.
x-frame-options	sameorigin	`X-Frame-Options` prevents this URL from being embedded in an `iframe`. This protects against clickjacking attacks. `sameorigin` allows this page to be displayed in an `iframe` on the same origin. This is the recommended setting.
x-nf-request-id	01m7a4kfe239n96a23jsax1ynq	A unique request identifier generated by Netlify. Netlify's customer support can use this ID to trace a request through its network.
x-permitted-cross-domain-policies	none	Instructs clients like Flash and Acrobat Reader what cross-domain policy they have to use. `none` is the most secure setting. Data can't be shared across domains.