Vary - [ HTTP 中文开发手册 ] - 在线原生手册

目录搜索

Guides Access control CORS Authentication Browser detection using the user agent Caching Caching FAQ Compression Conditional requests Connection management in HTTP 1.x Content negotiation Content negotiation: List of default Accept values Cookies CSP Messages Overview Protocol upgrade mechanism Proxy servers and tunneling Proxy servers and tunneling: Proxy Auto-Configuration (PAC) file Public Key Pinning Range requests Redirections Resources and specifications Resources and URIs Response codes Server-Side Access Control Session Guides: Basics Basics of HTTP Choosing between www and non-www URLs Data URIs Evolution of HTTP Identifying resources on the Web MIME Types MIME types: Complete list of MIME types CSP Content-Security-Policy Content-Security-Policy-Report-Only CSP: base-uri CSP: block-all-mixed-content CSP: child-src CSP: connect-src CSP: default-src CSP: font-src CSP: form-action CSP: frame-ancestors CSP: frame-src CSP: img-src CSP: manifest-src CSP: media-src CSP: object-src CSP: plugin-types CSP: referrer CSP: report-uri CSP: require-sri-for CSP: sandbox CSP: script-src CSP: style-src CSP: upgrade-insecure-requests CSP: worker-src Headers Accept Accept-Charset Accept-Encoding Accept-Language Accept-Ranges Access-Control-Allow-Credentials Access-Control-Allow-Headers Access-Control-Allow-Methods Access-Control-Allow-Origin Access-Control-Expose-Headers Access-Control-Max-Age Access-Control-Request-Headers Access-Control-Request-Method Age Allow Authorization Cache-Control Connection Content-Disposition Content-Encoding Content-Language Content-Length Content-Location Content-Range Content-Type Cookie Cookie2 Date DNT ETag Expect Expires Forwarded From Headers Host If-Match If-Modified-Since If-None-Match If-Range If-Unmodified-Since Keep-Alive Large-Allocation Last-Modified Location Origin Pragma Proxy-Authenticate Proxy-Authorization Public-Key-Pins Public-Key-Pins-Report-Only Range Referer Referrer-Policy Retry-After Server Set-Cookie Set-Cookie2 SourceMap Strict-Transport-Security TE Tk Trailer Transfer-Encoding Upgrade-Insecure-Requests User-Agent User-Agent: Firefox Vary Via Warning WWW-Authenticate X-Content-Type-Options X-DNS-Prefetch-Control X-Forwarded-For X-Forwarded-Host X-Forwarded-Proto X-Frame-Options X-XSS-Protection Methods CONNECT DELETE GET HEAD Methods OPTIONS PATCH POST PUT Status 100 Continue 101 Switching Protocols 200 OK 201 Created 202 Accepted 203 Non-Authoritative Information 204 No Content 205 Reset Content 206 Partial Content 300 Multiple Choices 301 Moved Permanently 302 Found 303 See Other 304 Not Modified 307 Temporary Redirect 308 Permanent Redirect 400 Bad Request 401 Unauthorized 403 Forbidden 404 Not Found 405 Method Not Allowed 406 Not Acceptable 407 Proxy Authentication Required 408 Request Timeout 409 Conflict 410 Gone 411 Length Required 412 Precondition Failed 413 Payload Too Large 414 URI Too Long 415 Unsupported Media Type 416 Range Not Satisfiable 417 Expectation Failed 426 Upgrade Required 428 Precondition Required 429 Too Many Requests 431 Request Header Fields Too Large 451 Unavailable For Legal Reasons 500 Internal Server Error 501 Not Implemented 502 Bad Gateway 503 Service Unavailable 504 Gateway Timeout 505 HTTP Version Not Supported 511 Network Authentication Required Status

文字

VaryHTTP 响应头决定如何满足未来的请求头，以决定一个缓存的响应是否可以使用，而不是请求从源服务器一个新的一个。服务器使用它来指示在内容协商算法中选择资源表示时使用哪个标头。

Vary头应该在设置304 Not Modified完全一样会被设定在相当的反应200 OK响应。

Header type	Response header
Forbidden header name	no

句法

Vary: *Vary: <header-name>, <header-name>, ...

指令

*每个 URL 的请求应该被视为一个独一无二且不可缓存的请求。指出这一点的更好方法是使用Cache-Control: private，它更清晰地阅读，并且表示该对象不应该被永久存储。<header-name> 在决定是否需要时考虑的逗号分隔的标题名列表可以使用缓存的响应。

例子

动态服务

使用Vary: User-Agent标题时，缓存服务器在决定是否从缓存中提供页面时应考虑用户代理。例如，如果您向移动用户提供不同的内容，它可以帮助您避免缓存可能错误地将您的网站的桌面版本提供给移动用户。它可以帮助谷歌和其他搜索引擎发现一个页面的移动版本，并可能告诉他们不需要隐藏。

Vary: User-Agent

产品规格

Specification	Title
RFC 7231, section 7.1.4: Vary	Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content

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

小心变化 - IE6-9 中的变化头问题另请参阅

Cache-Control

User-Agent