Accept

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 (en-US) 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 (en-US)
Forbidden header name (en-US) no
CORS-safelisted request header (en-US) 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 (en-US) 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 (en-US) 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

Specification
HTTP Semantics
# field.accept

瀏覽器相容性

BCD tables only load in the browser

參見