Web & TLS
Open HTTP Headers →Capture the response before changing configuration
Run HTTP Headers against the public hostname, then keep the response status and headers together. Headers describe that particular response; they are not a complete inventory of every resource on the site. A CDN, proxy and application may each contribute fields. Repeat the same target and IP version when comparing a before-and-after deployment.
Check the content and redirect context
Content-Type describes the returned representation. If a stylesheet URL returns HTML, a browser can reject it rather than apply the page’s styling. Location identifies a destination when used in a redirect response; inspect the associated status as well. Server or proxy-identification headers can offer clues, but names can be hidden or customized and should not be treated as reliable version evidence.
Read caching directives together
Cache-Control describes caching instructions, while other fields can expose age or validation information. A cache hit does not automatically mean a response is stale; it means a stored response was used according to that cache’s behavior. Diagnose the specific symptom: old HTML, an old asset, or a path that returns the wrong content. Compare the relevant response and deployment state before purging every cache.
Choose a targeted follow-up
Use Redirect Checker for the request’s redirect path and Security Headers for browser-protection policy findings. For problems affecting only one resource, inspect that exact resource in browser developer tools or your own HTTP client; a hostname-level lookup cannot represent every path. If the browser and checker disagree, compare cookies, request method, IP family and the endpoint being served.
Worked example
Illustrative example — not a live test Expected resource: application stylesheet Returned Content-Type: text/html Next step: inspect routing and asset deployment, not the font family.
What to check next
- Keep status, headers and the checked target together.
- Compare equivalent requests across repeated checks.
- Inspect an affected asset directly when the symptom is path-specific.
Common questions
Do these headers describe every page on the domain?
No. Applications and proxies can return different values for different paths and responses.
Does Cache-Control identify the cause of every stale page?
No. It is evidence to combine with the actual response, cache behavior and deployed files.