[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["没有我需要的信息","missingTheInformationINeed","thumb-down"],["太复杂/步骤太多","tooComplicatedTooManySteps","thumb-down"],["内容需要更新","outOfDate","thumb-down"],["翻译问题","translationIssue","thumb-down"],["示例/代码问题","samplesCodeIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC):2008-08-01。"],[[["\u003cp\u003eThis series of blog posts focuses on the \u003ccode\u003e404\u003c/code\u003e response code, which indicates a "Not Found" error when a webserver cannot locate the requested webpage/file.\u003c/p\u003e\n"],["\u003cp\u003eUnderstanding response codes, like the common \u003ccode\u003e200\u003c/code\u003e for "OK" or \u003ccode\u003e301\u003c/code\u003e for "Moved Permanently," is important as they represent the webserver's status in response to a request.\u003c/p\u003e\n"],["\u003cp\u003eA \u003ccode\u003e404\u003c/code\u003e error occurs when a user clicks a link, but the linked webpage/file is missing or inaccessible due to issues like a broken or mistyped URL.\u003c/p\u003e\n"],["\u003cp\u003eThe upcoming posts will provide guidance on optimizing the user experience and search engine handling of \u003ccode\u003e404\u003c/code\u003e errors.\u003c/p\u003e\n"]]],["Webservers use numeric response codes to indicate the status of a URL request. A `404` code signifies that a requested file was \"Not Found.\" When a user requests a webpage, the server searches for the corresponding file. If the file isn't found, the server should return a `404` error. Future posts will discuss optimizing `404` errors for both users and search engines. Response codes such as `200` means the file is found and `301` means the file has been permanently moved.\n"],null,["# It's 404 week at Webmaster Central\n\nMonday, August 11, 2008\n\n\nThis week we're publishing several blog posts dedicated to helping you with one response code:\n`404`.\n[Response codes](https://wikipedia.org/wiki/List_of_HTTP_status_codes)\nare a numeric status (like `200` for \"OK\", `301` for \"Moved Permanently\")\nthat a webserver returns in response to a request for a URL. The `404` response code\nshould be returned for a file \"Not Found\".\n\n\nWhen a user sends a request for your webpage, your webserver looks for the corresponding file for\nthe URL. If a file exists, your webserver likely responds with a `200` response code\nalong with a message (often the content of the page, such as the HTML).\n\n\nSo what's a `404`? Let's say that in the link to \"Visit Google Apps\" above, the link is\nbroken because of a typing error when coding the page. Now when a user clicks \"Visit Google Apps\",\nthe particular webpage/file isn't located by the webserver. The webserver should return a\n`404` response code, meaning \"Not Found\".\n\n\nNow that we're all on board with the basics of `404` errors, stay tuned for even more\ninformation on making `404` errors good for users and for search engines.\n\nWritten by [Maile Ohye](/search/blog/authors/maile-ohye), Developer Programs Tech Lead"]]