HTTP参考手册

状态 | Status

304 Not Modified

HTTP 304 Not Modified客户端重定向响应代码指示不需要重新传输请求的资源。这是对缓存资源的隐式重定向。这发生在请求方法是安全的时候，比如一个 GET或者一个HEAD请求，或者当请求是有条件的并且使用一个 If-None-Match或者一个If-Modified-Since标头时。

等效200 OK响应会包括头Cache-Control，Content-Location，Date，ETag，Expires，和Vary。

许多开发人员工具的浏览器网络面板会产生无关的请求，导致304响应，因此开发人员可以看到对本地缓存的访问。

状态

304 Not Modified

规范

规范	标题
RFC 7232，第4.1节：304未修改	超文本传输协议（HTTP / 1.1）：条件请求

浏览器兼容性

Feature	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic Support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

Feature	Android	Chrome for Android	Edge mobile	Firefox for Android	IE mobile	Opera Android	iOS Safari
Basic Support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

兼容性说明

如果此响应错误地包含持久连接上的主体，则浏览器行为会有所不同。有关更多详细信息，请参阅204无内容

If-Modified-Since

If-None-Match

状态 | Status相关

1.100 Continue
2.101 Switching Protocols
3.200 OK
4.201 Created
5.202 Accepted
6.203 Non-Authoritative Information
7.204 No Content
8.205 Reset Content
9.206 Partial Content
10.300 Multiple Choices
11.301 Moved Permanently
12.302 Found
13.303 See Other
14.307 Temporary Redirect
15.308 Permanent Redirect
16.400 Bad Request
17.401 Unauthorized
18.403 Forbidden
19.404 Not Found
20.405 Method Not Allowed
21.406 Not Acceptable
22.407 Proxy Authentication Required
23.408 Request Timeout
24.409 Conflict
25.410 Gone
26.411 Length Required
27.412 Precondition Failed
28.413 Payload Too Large
29.414 URI Too Long
30.415 Unsupported Media Type
31.416 Range Not Satisfiable
32.417 Expectation Failed
33.426 Upgrade Required
34.428 Precondition Required
35.429 Too Many Requests
36.431 Request Header Fields Too Large
37.451 Unavailable For Legal Reasons
38.500 Internal Server Error
39.501 Not Implemented
40.502 Bad Gateway
41.503 Service Unavailable
42.504 Gateway Timeout
43.505 HTTP Version Not Supported
44.511 Network Authentication Required
45.Status

HTTP

超文本传输协议（ HTTP，HyperText Transfer Protocol ) 是互联网上应用最为广泛的一种网络协议。所有的 WWW 文件都必须遵守这个标准。

HTTP目录

1.指南 \| Guides
2.指南：基础 \| Guides: Basics
3.CSP
4.标题 \| Headers
5.方法 \| Methods
6.RFC 2616: HTTP/1.1
7.RFC 4918: WebDAV
8.RFC 5023: The Atom Publishing Protocol
9.RFC 7230: Message Syntax and Routing
10.RFC 7231: Semantics and Content
11.RFC 7232: Conditional Requests
12.RFC 7233: Range Requests
13.RFC 7234: Caching
14.RFC 7235: Authentication
15.状态 \| Status
16.HTTP 请求方法
17.HTTP状态码
18.HTTP 响应头信息
19.HTTP 教程