Content-Language header
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The HTTPContent-Languagerepresentation header is used to describe the language(s) intended for the audience, so users can differentiate it according to their own preferred language.
For example,Content-Language: de-DE indicates that the document is intended for German language speakers. The document may be written in English, not German, as part of a language course for German speakers. To indicate the language the document iswritten in, use thelang attribute instead.
If noContent-Language is specified, the default is that the content is intended for all language audiences. Multiple language tags are also possible, as well as applying theContent-Language header to various media types and not only to textual documents.
| Header type | Representation header |
|---|---|
| Forbidden request header | No |
| CORS-safelisted response header | Yes |
| CORS-safelisted request header | Yes* |
* Values can only be0-9,A-Z,a-z, a space, or the characters*,-.;=.
Syntax
Content-Language: de-DEContent-Language: en-USContent-Language: de-DE, en-CADirectives
language-tagMultiple language tags are separated by a comma. Each language tag is a sequence of one or more case-insensitive subtags, each separated by a hyphen character (
-). In most cases, a language tag consists of a primary language subtag that identifies a broad family of related languages (e.g.,en= English) and is optionally followed by a series of subtags that refine or narrow that language's range (e.g.,en-CA= the variety of English as communicated in Canada).
Note:Languages are specified usingBCP 47 language tags, which rely on theISO 639 standard (quite often theISO 639-1 code list) forlanguage codes to be used.
Examples
Indicating the language a document is written in
The globallang attribute is used on HTML elements to indicate the language of an entireHTML document or parts of it.
<html lang="de"> …</html>Donot use this meta element to state the document language, as shown below:
<meta http-equiv="content-language" content="de" />Indicating a target audience for a resource
TheContent-Language header is used to specify thepage's intended audience and can indicate that this is more than one language.
Content-Language: de, enSpecifications
| Specification |
|---|
| HTTP Semantics # field.content-language |