Accept
HTTP 請求標頭(以 MIME type 標示)會對伺服器告知用戶端可解讀的內容類型。伺服器可以透過 content negotiation 來選用可行的協定,並以 Content-Type
標頭告知用戶端。針對本標頭,瀏覽器可以根據完成請求的脈絡,來決定適合的數值:像是擷取 CSS 時,給予的值就會和圖片、影像、腳本不一樣。
標頭類型 | Request header |
---|---|
Forbidden header name | no |
CORS-safelisted request header | yes, with the additional restriction that values can't contain a CORS-unsafe request header byte: "():<>?@[\]{} , Delete, Tab and control characters: 0x00 to 0x19. |
語法
Accept: <MIME_type>/<MIME_subtype> Accept: <MIME_type>/* Accept: */* // Multiple types, weighted with the quality value syntax: Accept: text/html, application/xhtml+xml, application/xml;q=0.9, image/webp, */*;q=0.8
指令
<MIME_type>/<MIME_subtype>
- 一個精確的 MIME type,例如
text/html
。 <MIME_type>/*
- 一個不指定子類的 MIME type。
image/*
會配對到image/png
,image/svg
,image/gif
和等圖片類型。 */*
- 所有 MIME type
;q=
(q-factor weighting)- Any value used is placed in an order of preference expressed using relative quality value called the weight.
示例
Accept: text/html Accept: image/* // General default Accept: */* // Default for navigation requests Accept: text/html, application/xhtml+xml, application/xml;q=0.9, */*;q=0.8
規範
規範 | 標題 |
---|---|
RFC 7231, section 5.3.2: Accept | Hypertext Transfer Protocol (HTTP/1.1): Semantics and Context |
瀏覽器相容性
BCD tables only load in the browser
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
參見
- HTTP content negotiation
- Header with the result of the content negotiation:
Content-Type
- 類似標頭:
TE
,Accept-Encoding
,Accept-Charset
,Accept-Language