HTTP status codes: complete list, meanings and SEO impact

HTTP status codes: complete list, meanings and SEO impact

HTTP status codes are three-digit server responses that tell a browser, crawler or API client what happened to a request. They fall into five classes: 1xx informational, 2xx success, 3xx redirection, 4xx client error and 5xx server error. Read the class first, then the exact code, to separate normal responses from redirects, missing resources and server failures.

The labels below follow the standard HTTP references used by MDN and the IANA registry. For the protocol's history, see MDN's evolution of HTTP guide; this guide focuses on what each code means now and when it matters for search.

Google-specific notes follow Google Search Central's guide to how HTTP status codes affect Google's crawlers, its redirect documentation, and Search Console Help on 404 and soft 404 errors.

How Google treats the main HTTP responses

Google can process a 2xx response for indexing, but a successful response does not guarantee indexing. If a page returns 200 OK while showing an empty page or error message, Google may treat it as a soft 404 rather than useful content.

For redirects, Google Search Central says permanent redirects such as 301 and 308 signal that the target should become canonical. Temporary redirects such as 302, 303 and 307 are followed, but Google generally keeps the source URL as the result it should show unless other canonical signals point elsewhere.

For missing pages, Google does not index URLs that return 4xx codes other than 429, and already indexed URLs are removed over time. Search Console Help says Google currently treats 410 Gone the same as 404 Not Found; use 410 when you know the removal is permanent, not because it has a separate ranking benefit.

For overloaded servers, Google treats 429 as a server-error signal. Persistent 5xx and 429 responses can slow crawling, and URLs that keep returning server errors can eventually be dropped from Google's index.

1xx informational responses

1xx responses are interim messages. They tell the client that the request has been received or that protocol-level work is happening before the final response.

100 Continue

100 Continue means the first part of the request has been received and the client can keep sending the rest. It is most useful when a client wants confirmation before sending a large request body.

101 Switching Protocols

101 Switching Protocols means the server has accepted an Upgrade request and is switching to the protocol named in the response. Keep this tied to the HTTP upgrade mechanism; it is not a general performance signal.

102 Processing

102 Processing is a WebDAV interim response meaning the server has accepted a complete request and is still processing it. It is rare on normal websites and should not be described as a general long-running-task pattern.

103 Early Hints

103 Early Hints lets a server send preliminary Link headers before the final response. It is used so clients can start preloading or preconnecting while the server prepares the main response.

2xx successful responses

2xx responses mean the request was received, understood and accepted. For SEO, a 2xx page can be considered for indexing, but Google still evaluates the content it receives.

200 OK

200 OK means the request succeeded. For a normal GET request, the response body contains the requested resource, such as an HTML page, image or JSON payload.

201 Created

201 Created means the request succeeded and created one or more new resources. APIs often use it after a successful POST, usually with a Location header or body pointing to the new resource.

202 Accepted

202 Accepted means the request has been received but has not yet been completed. It is common for queued jobs, batch processes and asynchronous APIs where the final outcome will be handled elsewhere.

203 Non-Authoritative Information

203 Non-Authoritative Information means the response metadata has been modified by a proxy or copy rather than returned exactly from the origin server. It is uncommon, but it is part of the standard success class.

204 No Content

204 No Content means the request succeeded and there is no response body to send. It is often used after an update or delete action where the client does not need a fresh representation.

205 Reset Content

205 Reset Content means the request succeeded and the client should reset the document view that sent the request. It is designed for forms or interfaces that should be cleared after a successful action.

206 Partial Content

206 Partial Content means the server is returning only the requested range of a resource. It is common for media files, downloads and resumable transfer behaviour.

3xx redirection messages

3xx responses tell the client to take another action, usually by requesting a different URL or using cached content. Use the permanent or temporary version that matches the real move.

300 Multiple Choices

300 Multiple Choices means more than one representation is available and the user agent or user should choose one. It is standard but rarely used because HTTP does not define a single automatic choice mechanism.

301 Moved Permanently

301 Moved Permanently means the resource has a new permanent URL. For Google, a permanent redirect is a canonicalisation signal for the target URL; in SEO language, this is often discussed through link equity, but the HTTP code itself only says the move is permanent.

302 Found

302 Found means the resource is temporarily available at a different URL and clients should keep using the original URL for future requests. Google follows it, but treats it as temporary rather than as a permanent canonical move.

303 See Other

303 See Other tells the client to retrieve another URI with a GET request. It is often used after form submissions or API actions when the response should point to a separate result page.

304 Not Modified

304 Not Modified is a caching response. It tells the client that the cached version can be reused because the resource has not changed since the conditional request.

307 Temporary Redirect

307 Temporary Redirect is the method-preserving version of a temporary redirect. A client that sent a POST should repeat the redirected request as POST, not silently change it to GET.

308 Permanent Redirect

308 Permanent Redirect is the method-preserving version of a permanent redirect. Google treats it like 301 for redirect handling, while HTTP clients also know not to change the request method.

4xx client error responses

4xx responses mean the request appears to be wrong, unauthorised, blocked or aimed at a resource that cannot be served. For Google Search, 4xx responses other than 429 tell Google not to use the content from that URL.

400 Bad Request

400 Bad Request means the server cannot or will not process the request because it appears malformed or invalid. Common causes include bad syntax, invalid framing, oversized request data or deceptive routing.

401 Unauthorized

401 Unauthorized means authentication is required or has failed. Despite the label, its practical meaning is "unauthenticated", and the response should include the authentication challenge the client needs.

402 Payment Required

402 Payment Required is reserved for payment-related uses, but no broad standard convention exists. You may see it in APIs, but it is rarely used for ordinary web pages.

403 Forbidden

403 Forbidden means the server understood the request but refuses to authorise access. Unlike 401, retrying with basic authentication is not the expected fix unless the server tells the client otherwise.

404 Not Found

404 Not Found means the server cannot find a current representation for the requested resource, or does not want to reveal that one exists. Google says ordinary 404s do not harm the whole site's indexing or ranking; if a URL should not exist, returning 404 is valid.

405 Method Not Allowed

405 Method Not Allowed means the server knows the request method, but the target resource does not allow it. For example, an endpoint may allow GET but reject DELETE.

406 Not Acceptable

406 Not Acceptable means the server cannot produce a response matching the client's Accept headers. It usually appears when content negotiation fails.

407 Proxy Authentication Required

407 Proxy Authentication Required is like 401, but the authentication is required by a proxy. The client must authenticate with the proxy before the request can proceed.

408 Request Timeout

408 Request Timeout means the server did not receive a complete request within the time it was prepared to wait. A client may repeat the request, usually over a fresh connection.

409 Conflict

409 Conflict means the request conflicts with the current state of the resource. APIs often use it for edit conflicts, duplicate records or version mismatches.

410 Gone

410 Gone means the resource is no longer available and the condition is likely permanent. Google groups 410 with 404 for index removal behaviour; choose 410 when the deletion is intentional and permanent.

411 Length Required

411 Length Required means the server refuses the request because it requires a Content-Length header. The client can retry with a valid length value.

412 Precondition Failed

412 Precondition Failed means one or more conditional request headers evaluated to false. It protects updates from being applied when the resource state is not what the client expected.

413 Content Too Large

413 Content Too Large means the request body exceeds the size the server is willing or able to process. Upload limits and oversized API payloads are common causes.

414 URI Too Long

414 URI Too Long means the target URI is longer than the server is willing to interpret. It often comes from excessive query-string data that should be moved into the request body.

415 Unsupported Media Type

415 Unsupported Media Type means the request body uses a format the server or resource does not support. APIs return it when the Content-Type is wrong or the uploaded file type is not accepted.

416 Range Not Satisfiable

416 Range Not Satisfiable means the requested byte range cannot be served. This can happen when a client asks for a range outside the size of the resource.

417 Expectation Failed

417 Expectation Failed means the server cannot meet the expectation given in the request's Expect header. It is most often connected with Expect: 100-continue.

418 I'm a Teapot

418 I'm a Teapot comes from the Hyper Text Coffee Pot Control Protocol joke RFC. It is a novelty code, not a practical status for real HTTP error handling.

421 Misdirected Request

421 Misdirected Request means the request reached a server that is not configured to produce a response for the scheme and authority in the request URI. It is most relevant with connection reuse and HTTP/2-style routing.

422 Unprocessable Content

422 Unprocessable Content means the request is syntactically valid but cannot be processed because of semantic errors. It is common in APIs for validation failures where 400 would be too broad.

425 Too Early

425 Too Early means the server is unwilling to process a request that might be replayed. It is tied to early data and replay-risk handling.

426 Upgrade Required

426 Upgrade Required means the server refuses the request under the current protocol but may accept it after the client upgrades. The response should name the required protocol in an Upgrade header.

428 Precondition Required

428 Precondition Required means the origin server requires the request to be conditional. It is designed to prevent lost updates when multiple clients might edit the same resource.

429 Too Many Requests

429 Too Many Requests means the user or client has sent too many requests in a given time window. For Googlebot, 429 is treated as a server-overload signal and can reduce crawl rate if it persists.

431 Request Header Fields Too Large

431 Request Header Fields Too Large means the server refuses the request because one header field, or the header section as a whole, is too large. Reducing cookies or custom headers can make the request valid.

451 Unavailable For Legal Reasons

451 Unavailable For Legal Reasons means the server cannot legally provide the requested resource. It is used when access is blocked because of a legal demand or legal restriction.

5xx server error responses

5xx responses mean the server failed to fulfil an apparently valid request. Short outages happen, but persistent 5xx responses can slow crawling and eventually remove affected URLs from Google's index.

500 Internal Server Error

500 Internal Server Error is a generic server-side failure. It means the server hit an unexpected condition and does not have a more specific 5xx response to use.

501 Not Implemented

501 Not Implemented means the server does not support the functionality required to fulfil the request. It is commonly tied to unsupported methods, though servers must still support GET and HEAD.

502 Bad Gateway

502 Bad Gateway means a server acting as a gateway or proxy received an invalid response from an upstream server. It often points to proxy, load balancer or upstream application failure.

503 Service Unavailable

503 Service Unavailable means the server is temporarily unable to handle the request, often because of overload or maintenance. If possible, send a Retry-After header so clients and crawlers know when to try again.

504 Gateway Timeout

504 Gateway Timeout means a gateway or proxy did not receive a timely response from an upstream server. It is the timeout counterpart to 502.

505 HTTP Version Not Supported

505 HTTP Version Not Supported means the server does not support the HTTP version used in the request. It should be rare on normal websites, but it is still a standard server-error response.

511 Network Authentication Required

511 Network Authentication Required means the client must authenticate to gain network access. It is mainly intended for intercepting proxies such as captive portals, not for ordinary website login pages.

How to check HTTP status codes

Use browser developer tools for a single URL: open the Network tab, reload the page and inspect the first document request. For a full site, use a crawler and fold the results into your SEO audit checklist so redirects, missing pages and server errors are reviewed together.

Use Google Search Console to see which status problems Google has actually encountered. Search Console is especially useful for submitted URLs, soft 404s, server errors and redirect issues that affect crawl and indexing.

Before pointing external placements at a URL, confirm the destination returns 200 OK and does not rely on avoidable redirect chains. That applies to existing-content placements such as curated links and to guest posts where a broken target wastes the placement.

Common fixes by status class

For 2xx, check that successful pages return useful content rather than empty templates or error copy. A thin error page served as 200 OK can become a soft 404.

For 3xx, match the redirect to the intent. Use 301 or 308 for permanent moves, 302 or 307 for temporary moves, and avoid long redirect chains.

For 4xx, leave genuine dead URLs as 404 or 410. Redirect only when there is a close replacement; sending every deleted URL to the homepage creates soft 404 risk.

For 429 and 5xx, fix server capacity, application errors or upstream dependencies before they become persistent. Google can slow crawl after repeated overload and server-error responses.

FAQs

What is the most common HTTP status code?

200 OK is the normal successful response for a page, file or API resource that can be served. It means the request succeeded, though Google may still decide not to index the content.

What status code should a deleted page return?

Use 404 Not Found if the page does not exist or you do not know whether the removal is permanent. Use 410 Gone when the page was intentionally removed and is not coming back.

Is a 302 bad for SEO?

No. A 302 Found response is correct for a temporary move. It becomes a problem when it is used for a permanent URL change, because Google treats permanent and temporary redirects differently.

Do 404 errors hurt the whole site?

No. Google's Search Console Help says 404 errors do not harm the site's indexing or ranking when the URLs should not exist. Fix submitted URLs, important backlinks and user-facing mistakes; ignore irrelevant dead URLs.

Which codes slow Google crawling?

Persistent 5xx responses and 429 Too Many Requests can slow crawling because Google treats them as server-overload or server-error signals. Crawl rate can increase again after the server returns stable 2xx responses.

Every fact and commercial claim in this guide was fact checked and verified on 16 July 2026.