Server Header Response Checker

Enter Website URL with prefix 'http://' or 'https://' and click on "Check" button to get the server header response code returned by web server.

HTTP Headers Explained in details:
Here's a list of common HTTP headers you might see. We have tried to keep it simple for you to understand in details.

Following are the common list of HTTP headers that server returns upon request and its explaination:

Status: Example HTTP/1.0 200 OK
Following are returned status codes and its meaning

  • Success Responses (2XX)
    • 200: Valid URL (OK)
    • 201 Created: Creation of a new resource
    • 202 Accepted: Processing has not been completed
    • 203 Non-Authoritative Information: Succeeded but the enclosed payload has been modified from that of the origin server's 200 OK response
    • 204 No Content: Not returned any content
    • 205 Reset Content: The server successfully processed the request, asks that the requester reset its document view.
    • 206 Partial Content: The server is delivering only part of the resource due to a range header sent by the client.
  • Redirection Messages (3XX)
    • 301: Page moved permanently
    • 302: Page moved temporarily
    • 303 See Other: Get the requested resource at another URI with a GET request
    • 304 Not Modified: The resource has not been modified
    • 307 Temporary Redirect: Get the requested resource at another URI with the same method
    • 308 Permanent Redirect: Get the requested resource at another URI with the same method, and the location is permanent.
  • Client Error Responses (4XX)
    • 400 Bad Request: The server could not understand the request
    • 401 Unauthorized: The client must authenticate itself to get the requested response.
    • 403 Forbidden: Does not have access rights to the content
    • 404 Not Found: The server can not find the requested URL
    • 410 Gone: Page / URL has been permanently deleted from the server
    • 414 URI Too Long: The URI requested by the client is longer than the server is willing to interpret
    • 415 Unsupported Media Type: The media format of the requested data is not supported by the server
    • 423 Locked: The resource that is being accessed is locked
    • 429 Too Many Requests: The user has sent too many requests in a given amount of time
    • 451 Unavailable For Legal Reasons: The user requests an illegal resource, such as a web page censored by a government.
  • Server Error Responses (5XX)
    • 500 Internal Server Error
    • 501 Not Implemented
    • 502 Bad Gateway
    • 503 Service Unavailable
    • 504 Gateway Timeout
    • 505 HTTP Version Not Supported
    • 506 Variant Also Negotiates
    • 507 Insufficient Storage
    • 508 Loop Detected: The server detected an infinite loop while processing a request
    • 510 Not Extended
    • 511 Network Authentication Required

Date: The date and time at which the server generated the response.

Connection: Common values are keep-alive or close. Example: Connection: keep-alive.

Server: Shows you about the software used by the server. Example: Server: Apache/2.4.41 (Ubuntu).

Content-Type: Media type of the resource. Example: Content-Type: text/html; charset=UTF-8.

Content-Length: Response body in bytes. Example: Content-Length: 4779.

Content-Encoding: Encoding / Compression used on the data. Example: Content-Encoding: gzip.

Last-Modified: When the resource was last modified. Example: Last-Modified: Tue, 20 Jun 2024 19:15:00 GMT.

ETag: A unique identifier for a specific version of the resource. Example: ETag: "34f7-5d7a7d8a34400".

Cache-Control: Directives for caching mechanisms in both requests and responses. Example: Cache-Control: no-cache, no-store, must-revalidate.

Expires: Shows response expiry date. Example: Expires: -1 means response should not be cached

Set-Cookie: Used to send cookies from the server to the user agent. Example: Set-Cookie: sessionId=abc123; Path=/; HttpOnly.

Location: Used in redirection or when a new resource has been created. Example: Location: https://example.com/new-page.

User-Agent: Contains information about the user agent originating the request. Example: User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36.

Accept: The media types that are acceptable for the response. Example: Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8.

Host: The domain name of the server (for virtual hosting), and the TCP port number on which the server is listening. Example: Host: example.com.

Referer: The address of the previous web page from which a link to the currently requested page was followed. Example: Referer: https://google.com.

Accept-Encoding: The encoding methods that are acceptable in the response. Example: Accept-Encoding: gzip, deflate, br.

Strict-Transport-Security: Enforces secure (HTTPS) connections to the server. Example: Strict-Transport-Security: max-age=31536000; includeSubDomains.

Content-Security-Policy: Helps to prevent XSS attacks by specifying the sources from which content is allowed to be loaded. Example: Content-Security-Policy: default-src 'self'; script-src 'self' https://trusted.cdn.com.

X-Frame-Options: Provides clickjacking protection. Example: X-Frame-Options: DENY.

X-Content-Type-Options: Prevents the browser from MIME-sniffing a response away from the declared content type. Example: X-Content-Type-Options: nosniff.

Referrer-Policy: Controls how much referrer information is included with requests. Example: Referrer-Policy: no-referrer-when-downgrade.

Permissions-Policy: Allows or denies the use of browser features such as geolocation, camera, etc. Example: Permissions-Policy: geolocation=(self).

SEO Tool

Server Header Checker: free online tool for faster website checks

The Server Header Checker helps website owners, developers and SEO specialists inspect the raw HTTP response returned by a web server. It is designed for quick daily checks, lightweight audits and practical troubleshooting when you need useful information without opening a full desktop application. Enter the relevant URL, domain or text, run the tool, and use the result as a starting point for decisions about SEO, security, development or content quality.

For SEO work, small technical details often decide whether a page is easy to crawl, share and trust. A page can have excellent content and still underperform if its technical signals are unclear. The Server Header Checker gives you a focused way to review one important part of that picture. It is especially helpful when you are launching a new website, moving to a new host, updating a CMS, checking a client request, or confirming that a developer change produced the expected result.

When to use this tool

Use this tool when you want to confirm whether a URL returns 200, 301, 302, 404 or 500, review redirects before a migration, check cache-control and content-type details and debug pages that behave differently for users and crawlers. It can also support routine maintenance, campaign checks, pre-launch reviews and competitor research. Because the interface is simple, it is useful for developers, SEO consultants, digital marketers, founders, support teams and students who want to understand what is happening behind a webpage without unnecessary complexity.

Why it matters

Clean server responses help search engines crawl pages efficiently, prevent redirect loops, and make technical SEO audits easier to explain. These checks are also useful because they create a shared language between technical and non-technical teams. Instead of guessing, you can copy the result, send it to a teammate, compare it with a previous scan, or use it as evidence in a website audit. Clear diagnostics reduce confusion and help teams prioritize the next action.

Search engines and browsers reward websites that are fast, secure, well structured and consistent. Tools like this do not replace a full technical audit, but they make the first layer of investigation much faster. If something looks wrong, the result can point you toward DNS settings, server configuration, metadata, content management settings, SSL certificates, redirects, structured data, security policies or frontend layout issues. That makes the tool valuable for both quick fixes and deeper analysis.

Best practices

Run the check on the final public URL whenever possible, including the correct protocol and path. Test both important landing pages and representative inner pages, because different templates can produce different results. After making a change, run the tool again and compare the output. For business-critical pages, combine this result with analytics, Search Console data, crawl reports and manual browser testing so you get both technical evidence and user-experience context.

The Tech-KB Server Header Checker is free to use and built for straightforward website diagnostics. Bookmark it for recurring audits, website launches, migration checks and everyday troubleshooting. A few minutes of verification can prevent broken previews, missed SEO opportunities, security oversights, incorrect redirects, expired certificates, malformed data or confusing mobile experiences before they affect real visitors.