Investigate content types, redirects and caching with response headers, without treating one lookup as a complete website audit.
A URL downloads a file when you expected a page, or an old version appears after an update. Response headers provide clues about what the server sent and how a client may handle it.
Focus on fields relevant to the problem
Content-Type describes the representation, Location can indicate a redirect, and Cache-Control supplies caching directives. The MDN header reference explains individual fields.
For an outdated image, inspect the cache-related headers and actual asset URL instead of collecting every server detail. A page and its images can have different rules.
Inspect the exact resource
- Open the HTTP headers lookup.
- Enter the public URL you are troubleshooting.
- Review the returned headers and response context.
- Compare with the browser behavior.
- Record the observation before changing configuration.
If a redirect is involved, inspect the route as well as a single response. Otherwise, you may be reading the headers of an intermediate address rather than the final resource.
Keep the limits in view
Responses can vary by request method, authentication, location and server configuration. A public lookup may not reproduce a signed-in browser's response. Some services also restrict automated requests.
Headers alone do not prove that a site is secure, fast or correctly indexed. Use them to answer a specific question, then follow the relevant platform documentation before changing unfamiliar directives.
For a content problem, such as the wrong page title, inspect the HTML metadata separately. Troubleshooting is easier when each check has a clear purpose.
Try the lookup with the redirect guide. Create a r37dy account when you need to maintain the links around your site.