HEADER CHECKER

Check HTTP Response Headers

Enter a public URL to inspect the HTTP status, final destination and response headers returned by the server.

How to check HTTP headers

  1. Enter a complete public URL.
  2. Select Check Headers.
  3. Review the initial status and any redirect path supported by the tool.
  4. Inspect the final response headers.
  5. Follow a focused checker when a header affects crawling, caching or content delivery.

What are HTTP response headers?

HTTP response headers are fields a server sends alongside a response. They describe how the response should be interpreted, cached, redirected or handled by a client.

Headers are separate from the HTML body. A page can have valid HTML while returning an unexpected status, content type, caching rule or crawler directive.

Use View Source when you need to inspect the HTML response body rather than the surrounding header fields.

What can an HTTP header checker show?

Depending on the response and implemented features, a header report may include:

  • HTTP status code
  • Final URL
  • Redirect locations
  • Content-Type
  • Content-Length when provided
  • Cache-Control
  • Expires
  • Last-Modified
  • ETag
  • Content-Encoding
  • X-Robots-Tag
  • Security-related response fields that are present

The absence of a field should be reported as an observation, not automatically scored as an error without context.

Understanding common status codes

Status family General meaning
2xx The request was successfully handled
3xx The client is directed to another location or representation
4xx The requested resource could not be provided as requested
5xx The server failed while handling the request

A status must be interpreted in context. For example, a redirect may be intentional, while a 200 response can still contain an error-like or empty page.

Why redirects matter

Redirects can be useful when a URL has moved, but unnecessary chains add extra requests and can make troubleshooting harder.

Review:

  • The initial URL
  • Each intermediate destination
  • The final status
  • Whether the final URL is canonical and intended
  • Whether internal links point directly to the final destination

Headers related to crawling and indexing

X-Robots-Tag can communicate crawler directives in the HTTP response. It is especially relevant for non-HTML resources or situations where a directive is not placed in an HTML meta element.

A header checker should display the exact value found. It should not claim that the page is indexed or not indexed without additional evidence.

Use the Robots.txt Checker to test crawler access rules, and use the SEO Checker to review other page-level indexability signals.

Caching and content delivery headers

Caching headers can influence how browsers and intermediaries reuse a response. Their ideal configuration depends on the resource type, update frequency and application architecture.

A tool may show fields such as Cache-Control, Expires, ETag or Last-Modified, but it should avoid applying one universal rule to every webpage and asset.

Security-related headers

Some headers can support browser security behavior. Their correct use depends on the application, and a simple presence check is not a complete security audit.

Do not treat a header score as proof that a website is secure. Configuration quality, policy contents, browser support and the wider application all matter.

Common reasons a header check fails

  • The hostname cannot be resolved
  • The server times out
  • The target blocks automated requests
  • A redirect leads to an unsupported destination
  • TLS negotiation fails
  • The URL points to a private or restricted network
  • The response exceeds tool limits

Related SolViewer tools

Frequently asked questions

Are HTTP headers visible in View Source?

No. View Source displays the HTML body. HTTP response headers are separate metadata sent with the response.

Does a 200 status mean the page is healthy?

Not necessarily. It means the request was handled successfully at the HTTP level. The page can still contain an error message, poor content or conflicting indexability signals.

Is every redirect bad for SEO?

No. Redirects are necessary when URLs move. Problems arise when redirects are incorrect, unnecessary, chained or inconsistent with internal links and canonicals.

Can this tool confirm that a page is indexed?

No. Response headers can reveal relevant directives and statuses, but indexation must be checked with search-engine data and the deployed page’s complete signals.

Is a security-header score a security audit?

No. Header checks cover only a limited part of application security and must be interpreted in context.