In computer network communications, the HTTP 404, 404 not found, 404, 404 error, page not found, or file not found error message is a hypertext transfer protocol (HTTP) standard response code, to indicate that the browser was able to communicate with a given server, but the server could not find what was requested. The error may also be used ...

404 是一个 http 错误代码，指的是网页不存在。 这些错误代码是一个叫 Tim Berners-Lee定义的。 他在 1990 年开发了世界上第一款网页浏览器。

404相信很多人在浏览网页的过程中都有遇到过，只是非业内人员只知道叫网站打不开了。 而404是网站打不开服务器返回的其中一种状态码，并不是所有的网站打不开都会返回404，也有可能是403、502、503等状态码。

浏览器发送HTTP请求到服务器，服务器给出应答，正常情况下返回状态码200，同时应答中携带返回的数据（比如页面数据），如果请求错误或服务器无法给出应答，则返回各种错误状态码。 404的状态码标识请求的URI (也就是网页地址)不存在。 The server has not found anything matching the Request-URI. No. permanent. The 410 (Gone) status code SHOULD be used if the server. resource is permanently unavailable and has no forwarding address. response is …

2018年2月23日 · HTTP 404或Not Found错误信息是HTTP的其中一种“标准回应信息”（HTTP 状态码），此信息代表客户端在浏览网页时，服务器无法正常提供信息，或是服务器无法回应且不知原因。 （为什么？ 知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见解，找到自己的解答」为品牌使命。 知乎凭借认真、专业、友善的社区氛围、独特的产品机制以及结构化和易获得的优质内容，聚集了中文 …

2017年12月26日 · 实际上，“404错误”信息通常是当目标页面被更改、移除，或是客户端输入页面地址错误后显示的页面。 久而久之，人们也就习以为常的用404代表服务器未找到文件的错误代码了。

2023年1月31日 · Your browser displays the error message 404 Not Found instead the desired web page? The solution is easy - an HTTP 404 error page appears when a web page can’t be found. See why this happens and solutions to fix the error 404 not found!

2023年2月18日 · A 404 error number indicates that the requested page could not be located. When a page loads in a browser, the HTTP header contains a response status code that is normally hidden from view. Status codes are issued by a server in response to a client’s request made to the server.

2024年4月8日 · At its core, a 404 error is a standard HTTP response code that means the server could not find the specific resource the client requested. However, the reason behind this absence can vary, ranging from the resource being removed or moved without proper redirection to the user mistyping a URL.

There are many different reasons you might come across a 404 error as it’s easy to accidentally create a dead link. Some of the most common reasons why 404 errors occur include: The URL, or its actual content (files, images, etc.) was either moved or deleted, and internal links weren’t adjusted to compensate