HTTP Response Status Code Checker

What an HTTP status code is

A status code is the three-digit answer a web server gives when a client requests a URL. The first digit groups the response into a family, and the other two identify the specific condition. The code is part of the protocol, not part of the page content.

The checker requests each address, records the code and maps common codes to a short reason such as OK, Not Found or Moved Permanently. It also labels the family so a long list is easier to scan.

The five families

1xx responses are informational and rare in normal browsing. They mean the request was received and processing continues. A checker may not display them because the final response arrives later.

2xx means success. 200 is the ordinary OK response. 201 means a resource was created, 204 means success with no body, and other 2xx codes describe partial or accepted requests.

3xx means the client must take another step, usually a redirect. 301 is permanent, 302 is temporary, 304 means the cached copy is still valid, and 307 or 308 preserve the request method. A redirect is not automatically an error, but a chain of them is worth fixing.

4xx means the request is the problem. 400 is a bad request, 401 means authentication is required, 403 means forbidden, 404 means not found, and 429 means too many requests. These codes often appear for bots, expired sessions and mistyped addresses.

5xx means the server failed. 500 is a generic error, 502 is a bad gateway, 503 is unavailable and 504 is a gateway timeout. These are server-side problems, even when a particular request triggered them.

Common codes and what they usually mean

• 200 OK: the page was returned normally.
• 301 Moved Permanently: update links to the new URL.
• 302 Found: a temporary redirect, often used after a form submission.
• 304 Not Modified: the client's cached copy can be reused.
• 400 Bad Request: malformed syntax, headers or parameters.
• 401 Unauthorized: credentials are missing or invalid.
• 403 Forbidden: the server understood the request but refuses it.
• 404 Not Found: no resource at that address.
• 429 Too Many Requests: rate limiting is active.
• 500 Internal Server Error: an unhandled server-side failure.
• 502 Bad Gateway: an upstream service returned an invalid response.
• 503 Service Unavailable: the server is overloaded or in maintenance.

Redirects and the reported code

This checker does not silently follow redirects. It reports the first response, so a URL that redirects shows a 3xx code rather than the destination's 200. That is useful when you want to know whether an old address still redirects, but it means the reported code is not always the code of the final page.

If you need the destination, open the URL in a browser or use a redirect tracer that lists each hop. A single 301 is usually fine; a loop or a long chain wastes crawl budget and slows visitors.

Soft 404s and false positives

A page can return 200 and still be a missing-content page, with a friendly apology and no article. That is a soft 404. Status-code checking cannot detect it without looking at the content, so combine the code with a visual check for important pages.

The reverse also happens: a bot-protection layer may return 403 to the checker while the page loads normally in your browser. A login wall may return 302 to a sign-in page. Treat a surprising code as a clue, then confirm what a real visitor sees.

Batch checking

Paste one URL per line, up to ten addresses. The result table lists each URL, its code, the reason text and a family badge. The summary counts successes and groups the codes so you can see whether a deploy produced a pattern of 404s or 500s.

Use the batch for a sitemap sample, a set of redirects after a migration or a list of API endpoints. Keep the list short enough to review; ten URLs is a spot check, not a crawl.

Limits

The checker sends a simple GET request without your cookies, custom headers or authentication. Private and intranet addresses are rejected. Each URL must be valid and no longer than 2,048 characters.

It does not validate the page content, follow the redirect chain, test POST endpoints or measure performance. It is a status check, not a full SEO audit or uptime monitor.

Status codes and search engines

Search engines use status codes to decide what to do with a URL. A 200 is eligible to be indexed. A 301 passes signals to the new address and should be used for permanent moves. A 302 is a temporary signal and may keep the old URL in the index longer. A 404 or 410 tells crawlers the page is gone; 410 is more explicit but both can lead to removal over time.

A 5xx tells crawlers to come back later. Repeated 5xx responses can slow crawling and, if they persist, reduce trust in the site. A soft 404 is worse than a clear one because the server says success while the page has no content. Do not use robots.txt to hide a missing page; use a real 404 or a redirect.

Checking after a migration

Before a move, export a sample of important old URLs. After the move, check each one for a 301 to the correct new address, not to the homepage. Then check the new URLs return 200 and that their canonical tags point to themselves. A batch of ten is enough for a spot check; a full crawl is better for thousands of pages.

Watch for chains and loops: old URL to staging URL to final URL is a chain, and old URL to itself is a loop. Fix them at the server or redirect rule rather than adding another hop.

Frequently Asked Questions