Http status codeStatus code meaning
100The client SHOULD continue to send the request. This interim response is used to inform the client that part of its request has been accepted by the server and has not been rejected. The client SHOULD continue to send the remainder of the request, or ignore this response if the request is already completed. The server MUST send a final response to the client after the request is completed.
101The server has understood the client's request and will inform the client via the Upgrade message header to use a different protocol to complete the request. After sending the final empty line of this response, the server will switch to the protocol specified in the Upgrade message header. Such action should only be taken when there is a benefit to switching to a new protocol. For example, switching to a new HTTP version has advantages over an older version, or switching to a real-time and synchronous protocol to transfer resources that take advantage of such features.
102Status code extended by WebDAV (RFC 2518) indicating that processing will continue.
200The request has been successful, and the response header or data body expected by the request will be returned with this response.
201The request has been implemented, and a new resource has been created according to the request, and its URI has been returned with the Location header information. If the required resource cannot be created in time, '202 Accepted' should be returned.
202The server has accepted the request but has not yet processed it. Just as it could have been rejected, the request may or may not be executed in the end. In the case of asynchronous operations, there is no more convenient way to send this status code. The purpose of returning a 202 status code response is to allow the server to accept requests for other processes (such as a batch-based operation that is executed only once a day) without having to keep the client connected to the server until the batch operation is completed. The response to the request processing and returning a 202 status code should include some information indicating the current status of the processing in the returned entity, as well as a pointer to a processing status monitor or status prediction so that the user can estimate whether the operation has completed.
203The server has successfully processed the request, but the returned entity header meta-information is not the definitive set valid on the original server, but comes from a local or third-party copy. The current information may be a subset or superset of the original version. For example, the inclusion of metadata for the resource may result in the origin server knowing the superset of the meta-information. Use of this status code is not required, and is only appropriate when the response would return 200 OK without using this status code.
204The server successfully processed the request, but does not need to return any entity content, and hopes to return updated meta information. The response may return new or updated meta information in the form of entity headers. If these headers exist, they should correspond to the requested variables. If the client is a browser, the user's browser should retain the page that sent the request without making any changes to the document view, even though the new or updated meta information should be applied to the document in the user's browser's active view according to the specification. Since the 204 response is prohibited from containing any message body, it always ends with the first empty line after the message header.
205The server successfully processed the request and did not return any content. However, unlike the 204 response, the response returning this status code requires the requester to reset the document view. This response is mainly used to reset the form immediately after accepting user input so that the user can easily start another input. Like the 204 response, this response MUST NOT contain any message body and ends with the first blank line after the message headers.
206The server has successfully processed part of the GET request. HTTP download tools such as FlashGet or Xunlei use this type of response to resume downloads or to split a large document into multiple download segments for simultaneous download. The request must contain the Range header to indicate the content range that the client wants to obtain, and may contain If-Range as a request condition. The response must contain the following header fields: Content-Range is used to indicate the range of content returned in this response; if it is a multi-segment download with Content-Type multipart/byteranges, each multipart segment should contain a Content-Range field to indicate the content range of this segment. If the response contains Content-Length, its value must match the actual number of bytes in the content range it returns. Date ETag and/or Content-Location, if the same request should have returned a 200 response. Expires, Cache-Control, and/or Vary, if its value may be different from the corresponding value of other responses to the same variant. If this response request uses If-Range strong cache validation, then this response should not contain other entity headers; if this response request uses If-Range weak cache validation, then this response is prohibited from containing other entity headers; this avoids inconsistencies between cached entity content and updated entity header information. Otherwise, this response should include all entity header fields that should be returned in a 200 response. If the ETag or Last-Modified headers cannot be matched exactly, the client cache should not combine the content returned by the 206 response with any previously cached content. Any cache that does not support the Range and Content-Range headers is prohibited from caching the content returned by the 206 response.
207A status code extended by WebDAV (RFC 2518) indicating that the following message body will be an XML message and may contain a number of separate response codes, depending on the number of previous subrequests.
300The requested resource has a number of possible responses, each with its own unique address and browser-driven negotiation information. The user or browser can select a preferred address for redirection. Unless this is a HEAD request, the response SHOULD include an entity with a list of resource characteristics and addresses from which the user or browser can select the most appropriate redirection address. The format of this entity is determined by the format defined by Content-Type. The browser MAY automatically make the most appropriate choice based on the format of the response and the browser's own capabilities. Of course, RFC 2616 does not specify how such automatic selection should be made. If the server already has a preferred response choice, the URI of the response SHOULD be specified in the Location field; the browser MAY use this Location value as the address for automatic redirection. In addition, this response is cacheable unless otherwise specified.
301The requested resource has been permanently moved to a new location, and any future references to this resource should use one of the URIs returned in this response. Clients with link editing capabilities should automatically modify the requested address to the address returned by the server if possible. This response is cacheable unless otherwise specified. The new permanent URI should be returned in the Location field of the response. Unless this is a HEAD request, the entity of the response should contain a hyperlink to the new URI and a brief description. If this is not a GET or HEAD request, the browser must not automatically redirect unless the user confirms that the request conditions may have changed. Note: For some browsers using the HTTP/1.0 protocol, when the POST request they send receives a 301 response, the subsequent redirect request will become a GET method.
302The requested resource is now temporarily responding to requests from a different URI. Since such a redirect is temporary, the client should continue to send subsequent requests to the original address. This response is cacheable only if specified in Cache-Control or Expires. The new temporary URI SHOULD be returned in the Location field of the response. Unless this was a HEAD request, the entity of the response SHOULD contain a hyperlink to the new URI and a brief description. If this was not a GET or HEAD request, the browser MUST NOT automatically redirect unless confirmed by the user, because the conditions of the request might change. NOTE: Although RFC 1945 and RFC 2068 do not allow clients to change the request method when redirecting, many existing browsers treat a 302 response as a 303 response and use GET to access the URI specified in the Location field, regardless of the original request method. Status codes 303 and 307 were added to make it clear what the server expects from the client.
303The response to the current request can be found at another URI, and the client SHOULD access that resource using GET. This method exists primarily to allow script-activated POST requests to redirect to a new resource. The new URI is not a replacement reference for the original resource. Also, 303 responses MUST NOT be cached. However, the second request (the redirect) MAY be cached. The new URI SHOULD be returned in the Location field of the response. Unless this is a HEAD request, the entity of the response SHOULD contain a hyperlink to the new URI and a brief description. Note: Many browsers prior to HTTP/1.1 do not understand the 303 status correctly. If interaction with these browsers is a concern, the 302 status code should be sufficient, as most browsers handle 302 responses in exactly the way that the above specification requires clients to handle 303 responses.
304The server SHOULD return this status code if the client sent a conditional GET request and the request was granted, and the content of the document has not changed (either since the last access or according to the request conditions). A 304 response MUST NOT include a message-body and therefore always ends with the first blank line after the headers. The response MUST include the following headers: Date, unless the server does not have a clock. If servers without clocks follow these rules, proxies and clients MAY add the Date field to the response headers they receive (as specified in RFC 2068) and caches will work properly. ETag and/or Content-Location, if a 200 response would have been returned for the same request. Expires, Cache-Control, and/or Vary, if the values ​​might differ from those of previous responses to the same variant. If the request was made with strong cache validation, the response SHOULD NOT include any other entity-headers; otherwise (e.g., a conditional GET request with weak cache validation), the response MUST NOT include any other entity-headers; this avoids inconsistencies between cached entity content and updated entity-headers. If a 304 response indicates that an entity is not currently cached, caches MUST ignore the response and repeat the request without the restriction. If a 304 response is received requesting an update to a cache entry, the cache system must update the entire entry to reflect the values ​​of all fields updated in the response.
305The requested resource must be accessed through the specified proxy. The Location field will give the URI information of the specified proxy. The recipient needs to repeat a separate request to access the corresponding resource through this proxy. Only the original server can create a 305 response. Note: RFC 2068 does not specify that the 305 response is for redirecting a single request and can only be created by the original server. Ignoring these restrictions may lead to serious security consequences.
306In the latest version of the specification, the 306 status code is no longer used.
307The requested resource is now temporarily responding to requests from a different URI. Since such a redirection is temporary, the client should continue to send subsequent requests to the original address. This response is cacheable only if specified in Cache-Control or Expires. The new temporary URI should be returned in the Location field of the response. Unless this is a HEAD request, the entity of the response should contain a hyperlink to the new URI and a brief description. Because some browsers cannot recognize the 307 response, it is necessary to add the necessary information so that users can understand and make access requests to the new URI. If this is not a GET or HEAD request, the browser is prohibited from automatically redirecting unless confirmed by the user, because the conditions of the request may change.
4001. The semantics are incorrect and the current request cannot be understood by the server. Unless modified, the client should not resubmit this request. 2. The request parameters are incorrect.
401The current request requires user authentication. The response MUST include a WWW-Authenticate header message, appropriate for the requested resource, asking for user information. The client MAY repeat the request with an appropriate Authorization header message. If the current request already included Authorization credentials, then a 401 response indicates that the server has rejected those credentials. If a 401 response contains the same authentication challenge as a previous response, and the browser has already attempted authentication at least once, then the browser SHOULD display the entity contained in the response to the user, as it may contain relevant diagnostic information. See RFC 2617.
402This status code is reserved for possible future use.
403The server understood the request, but is refusing to perform it. Unlike a 401 response, authentication does not provide any assistance, and the request SHOULD not be repeated. If this was not a HEAD request, and the server wishes to explain why the request could not be performed, then the reason for the refusal SHOULD be given in the entity. Of course the server can also return a 404 response if it does not want the client to get any information.
404The request failed, and the resource requested was not found on the server. There is no information to tell the user whether this situation is temporary or permanent. If the server knows the situation, it should use the 410 status code to inform that the old resource is permanently unavailable due to some internal configuration mechanism problems, and there is no address to jump to. The 404 status code is widely used when the server does not want to reveal why the request was rejected or no other suitable response is available.
405The request method specified in the request line cannot be used to request the corresponding resource. The response must return an Allow header information to indicate the list of request methods that the current resource can accept. Since PUT and DELETE methods will write to the resources on the server, most web servers do not support or do not allow the above request methods in the default configuration, and will return 405 errors for such requests.
406The content characteristics of the requested resource cannot meet the conditions in the request header, so the response entity cannot be generated. Unless this is a HEAD request, the response should return an entity containing entity attributes and a list of addresses from which the user or browser can choose the most appropriate entity. The format of the entity is determined by the media type defined in the Content-Type header. The browser can make the best choice based on the format and its own capabilities. However, the specification does not define any standard for making such automatic choices.
407Similar to the 401 response, except that the client must authenticate with the proxy server. The proxy server must return a Proxy-Authenticate to query the identity. The client can return a Proxy-Authorization header for verification. See RFC 2617.
408Request timeout. The client did not complete a request within the time the server was prepared to wait. The client can submit this request again at any time without making any changes.
409The request cannot be completed due to a conflict with the current state of the requested resource. This code is only allowed to be used in such a situation: the user is considered to be able to resolve the conflict and will resubmit a new request. The response should contain enough information for the user to discover the source of the conflict. Conflicts usually occur in the processing of PUT requests. For example, in an environment where version checking is used, the version information attached to a PUT request to modify a specific resource conflicts with a previous (third-party) request. In this case, the server should return a 409 error to inform the user that the request cannot be completed. At this time, the response entity is likely to contain a difference comparison between the two conflicting versions, so that the user can resubmit the new version after the merge.
410The requested resource is no longer available on the server and no forwarding address is known. This condition should be considered permanent. Clients with link editing capabilities should remove all references to this address if possible with the user's permission. If the server does not know or cannot determine whether the condition is permanent, it should use the 404 status code. Unless otherwise specified, this response is cacheable. The purpose of the 410 response is mainly to help website administrators maintain their websites, notifying users that the resource is no longer available and that the server owner wishes all remote links to the resource to be removed. This type of event is common for limited-time, value-added services. Similarly, the 410 response is also used to inform clients that a resource originally belonging to a person is no longer available on the current server site. Of course, it is entirely up to the server owner to mark all permanently unavailable resources as '410 Gone' and how long to keep this mark.
411The server refuses to accept the request without a defined Content-Length header. After adding a valid Content-Length header indicating the length of the request message body, the client can submit the request again.
412The server failed to meet one or more of the preconditions given in the request header field when verifying the request. This status code allows the client to set preconditions in the request meta-information (request header field data) when obtaining resources, so as to prevent the request method from being applied to resources other than the expected content.
413The server refuses to process the current request because the size of the entity data submitted by the request exceeds the range that the server is willing or able to process. In this case, the server can close the connection to prevent the client from continuing to send this request. If this condition is temporary, the server should return a Retry-After response header to tell the client how much time it can try again.
414The length of the requested URI exceeds the length that the server can interpret, so the server refuses to provide service for the request. This is relatively rare. Common situations include: the form submission that should have used the POST method becomes the GET method, resulting in a query string that is too long. Redirect URI "black hole", for example, each redirection uses the old URI as part of the new URI, resulting in the URI being too long after several redirections. The client is trying to exploit security vulnerabilities in some servers to attack the server. Such servers use a fixed-length buffer to read or operate the requested URI. When the parameter after GET exceeds a certain value, a buffer overflow may occur, resulting in arbitrary code execution [1]. Servers without such vulnerabilities should return a 414 status code.
415For the current request method and the requested resource, the entity submitted in the request is not in a format supported by the server, so the request is rejected.
416If the request contains a Range request header, and any data range specified in the Range does not overlap with the available range of the current resource, and the request does not define an If-Range request header, the server should return a 416 status code. If the Range uses a byte range, this means that the first byte position of all data ranges specified in the request exceeds the length of the current resource. The server should also include a Content-Range entity header to indicate the length of the current resource when returning the 416 status code. This response is also prohibited from using multipart/byteranges as its Content-Type.
417The expectation specified in the request header Expect cannot be met by the server, or the server is a proxy server and there is clear evidence that the expectation cannot be met at the next node in the current route.
421The number of connections from the current client's IP address to the server exceeds the maximum range allowed by the server. Usually, the IP address here refers to the client address seen from the server (such as the user's gateway or proxy server address). In this case, the calculation of the number of connections may involve more than one end user.
422The number of connections from the current client's IP address to the server exceeds the maximum range allowed by the server. Usually, the IP address here refers to the client address seen from the server (such as the user's gateway or proxy server address). In this case, the calculation of the number of connections may involve more than one end user.
422The request is well-formed, but cannot be responded to due to semantic errors. (RFC 4918 WebDAV) 423 Locked The current resource is locked. (RFC 4918 WebDAV) 424 The current request failed due to an error in a previous request, such as PROPPATCH. (RFC 4918 WebDAV) 425 Defined in the WebDav Advanced Collections draft, but not in the WebDAV Sequenced Sets Protocol (RFC 3658).
426客户端应当切换到TLS/1.0。(RFC 2817)
449Extended by Microsoft to indicate that the request should be retried after performing appropriate actions.
500The server encountered an unexpected condition that prevented it from completing the request. Generally, this problem occurs when there is an error in the server's program code.
501The server does not support a feature required by the current request. When the server does not recognize the request method and cannot support its request for any resource.
502The server, acting as a gateway or proxy, received an invalid response from the upstream server while trying to perform the request.
503The server is currently unable to process the request due to temporary server maintenance or overload. This condition is temporary and will recover after some time. If the delay can be expected, the response can include a Retry-After header to indicate this delay. If no Retry-After information is given, the client SHOULD handle it the same way as a 500 response. Note: The existence of the 503 status code does not mean that the server must use it when it is overloaded. Some servers simply wish to refuse client connections.
504The server, acting as a gateway or proxy, did not receive a response in a timely fashion from an upstream server (the server identified by a URI, such as HTTP, FTP, LDAP) or a secondary server (such as DNS) while attempting to fulfill a request. Note: Some proxy servers return 400 or 500 errors when a DNS query times out.
505The server does not support, or refuses to support, the HTTP version used in the request. This implies that the server is unable or unwilling to use the same version as the client. The response SHOULD include an entity describing why the version is not supported and what protocols the server supports.
506Extended by the Transparent Content Negotiation Protocol (RFC 2295), indicates an internal configuration error on the server: the requested negotiation argument resource is configured to use itself in transparent content negotiation and is therefore not an appropriate focus in a negotiation process.
507The server is unable to store content necessary to fulfill the request. This condition is considered temporary. WebDAV(RFC 4918)
509The server reached a bandwidth limit. This is not an official status code, but it is still widely used.
510The policy required to obtain the resource is not satisfied.(RFC 2774)
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