The Accept-Charset
request HTTP header advertises which character set the client is able to understand Using content negotiation, the server then selects one of the proposal, use it and inform the client of its choice within the {{HTTPHeader("Content-Type")}} response header. Browser usually don't set this header as the default value defined for each content type is usually correct and transmitting it would allow for easier fingerprinting.
If the server cannot serve any matching language, it can theoretically send back a {{HTTPStatus("406")}} Not Acceptable
error code. But, for UX reasons, this is rarely done and the standard way is to ignore the Accept-Charset
header in this case.
In early versions of HTTP/1.1, a default charset (ISO-8859-1
) was defined. This is no more the case and now each content type may have its own default.
Header type | {{Glossary("Request header")}} |
---|---|
{{Glossary("Forbidden header name")}} | yes |
Syntax
Accept-Charset: <charset> // Multiple types, weighted with the q-factor syntax: Accept-Language: utf-8, iso-8859-1;q=0.5
Directives
<charset>
- A character set like
utf-8
oriso-8859-15
*
- Any charset no mentioned elsewhere in the header;
'*'
being used as a wildcard. ;q=
(q-factor weighting)- Any value used is placed in an order of preference expressed using relative quality factor called the weight.
Examples
Accept-Charset: iso-8859-1 Accept-Charset: utf-8, iso-8859-1;q=0.5 Accept-Language: utf-8, iso-8859-1;q=0.5, *;q=0.1
Specifications
Specification | Title |
---|---|
{{RFC("7231", "Accept-Charset", "5.3.3")}} | Hypertext Transfer Protocol (HTTP/1.1): Semantics and Context |
Browser compatibility
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/README.md and send us a pull request.
{{Compat}}
See also
- HTTP content negotiation
- Header with the result of the content negotiation: {{HTTPHeader("Content-Type")}}
- Other similar headers: {{HTTPHeader("TE")}}, {{HTTPHeader("Accept-Encoding")}}, {{HTTPHeader("Accept-Language")}}, {{HTTPHeader("Accept")}}