Html 5 meta content lang

Content-Language

The Content-Language representation 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, if » Content-Language: de-DE » is set, it says that the document is intended for German language speakers (however, it doesn’t indicate the document is written in German. For example, it might be written in English as part of a language course for German speakers. If you want to indicate which language the document is written in, use the lang attribute instead).

If no Content-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 the Content-Language header to various media types and not only to textual documents.

Header type	Representation header
Forbidden header name	no
CORS-safelisted response header	yes
CORS-safelisted request header	yes, with the additional restriction that values can only be 0-9 , A-Z , a-z , space or *,-.;= .

Syntax

Content-Language: de-DE Content-Language: en-US Content-Language: de-DE, en-CA 

Directives

Multiple 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 (» — «, %x2D ). 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: Language tags are formally defined in BCP 47, which rely on the ISO 639 standard (quite often the ISO 639-1 code list) for language codes to be used.

Examples

Indicating the language a document is written in

The global lang attribute is used on HTML elements to indicate the language of an entire HTML document or parts of it.

Do not use this meta element like this for stating a document language:

meta http-equiv="content-language" content="de" /> 

Indicating a target audience for a resource

The Content-Language header is used to specify the page’s intended audience and can indicate that this is more than one language.

Specifications

Browser compatibility

BCD tables only load in the browser

See also

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This page was last modified on Apr 11, 2023 by MDN contributors.

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Описание мета-тегов

Посмотрев HTML код разных сайтов возникает вопрос – зачем в нем так много мета-тегов и для чего они нужны? В данной статье представлены все самые встречающеюся теги с примерами и пояснениями.

Описание страницы

Title

Заголовок страницы, оптимальная длина 50-60 символов.

Description

Краткое описание страницы длинной 160-180 символов, используется в выводе результатов поиска.

Keywords

Содержит ключевые слова встречающихся на странице. Не более 20-ти слов и 3-х повторов.

Кодировка сайта

Application-Name

Название веб-приложения. Можно указать несколько названий для разных языковых локалей.

• В Android используется при добавлении сайта на главный экран.
• В Windows 8, 10 при добавлении сайта в панель приложений и плиткой в меню пуск.

Generator

Сообщает, с помощью какой программы был сгенерирован код страницы.

Author

Информация об авторе сайта.

Copyright

Информация о владельце сайта.

Reply-To

Указывает способ связи с автором страницы.

Content-Language

Указывает язык страницы. Используется поисковыми машинами при индексировании.

Help

Предоставляет ссылку на справку или e-mail.

Управление индексацией

Robots

Задает правила индексации для поисковых роботов.

Общие значения:

index , follow или all	Разрешено индексировать текст и ссылки на странице
noindex	Не индексировать текст страницы
nofollow	Не переходить по ссылкам на странице
noindex , nofollow или none	Запрещено индексировать текст и переходить по ссылкам
noarchive	Не показывать ссылку на сохраненную копию в поисковой выдаче

noyaca

Не использовать описание из Яндекс.Каталога для сниппета в результатах поиска

nosnippet	Запрещает показывать видео или фрагмент текста в результатах поиска
noimageindex	Запрещает указывать вашу страницу как источник ссылки для изображения
noodp	Не использовать описание из каталога DMOZ

Last-Modified

Альтернативно HTTP-заголовку Last-Modified задает дату последнего изменения для статических страниц.

Document-State

Определяет частоту индексации для поисковых роботов.

Revisit-After

Указывает как часто обновляется информация на сайте, и как часто поисковая система должна на него заходить.

Управление кэшированием

Cache-Control

Указывает как браузеру кэшировать страницу.

Допустимые значения:

public	Кэшируется все
private	Кэшируется браузером, но не proxy-сервером
no-cache	Запрещает кэширование
max-age=0	Сколько секунд хранить в кэше

Pragma

Expires

Дата окончания кэша браузера. Если указать прошедшую дату или 0, то документ не будет кэшироваться.

Canonical — предпочитаемый канонический адрес

Если у страницы есть дубликаты с одним содержанием и разными URL, например:

В rel=»canonical» указывается адрес, который будет считаться основным и будет использоваться в поисковой выдаче.

Prev

Указывает URL предыдущий страницы при пагинации.

Next

Указывает URL следующий страницы при пагинации.

Источник

HTTP headers, meta elements and language information

In addition to the lang (and/or xml:lang) attribute on the html tag, you may come across language information in HTML meta elements, or in the HTTP header which is served with an HTML page. Here we look at whether these are useful when declaring language for HTML content, and if so, how they should be used.

This article is (specifically) about language declarations in HTTP headers and meta elements. It’s not a general guide to setting language on an HTML page: for that, see Declaring language in HTML .

This article builds on the distinction between (1) using file metadata to identify the audience for the document, and (2) specifying the language used for the purpose of processing content. If you want to better understand the distinction see the article Types of language declaration.

The meta element

You may come across a language-related meta element near the top of an HTML file. It looks like this.

This use of the content-language value for an http-equiv attribute is deprecated by the HTML specification, and should no longer be used. Instead, you should always use a lang attribute on the html tag to declare the default language of the text in the page.

If you want to know why this approach is deprecated, see below. To learn about how to use the lang attribute, see Declaring language in HTML.

HTTP headers

When you retrieve a web page or resource from a server, the server sends with it various bits of information about the thing you are retrieving (metadata). It uses a format referred to as HTTP headers. One of the items you may find in such metadata is language related. See the last line in the example below that shows the HTTP response that accompanies this article.

Unlike the lang and xml:lang attributes, the value of the content attribute can be a comma-separated list of language tags. The example below declares the primary languages of the document to be (in equal measure) German, French and Italian.

If the name of the meta element wasn’t a clear enough clue, the fact that the value supports multiple languages indicates that this element is really about document level metadata. If you are to usefully indicate the language of a range of text, you have to be specific – it can only be in one language at a time. The meta element, then, is an in-document location for expressing metadata about the language of the intended audience of the document as a whole.

Until recently, few browsers paid any attention to this meta element. Then several major browsers began using this element, if there was no language attribute on the html tag, to set the default language of the text in the document (what you should use a language attribute on the html tag for). The way this was implemented was inconsistent, and therefore unreliable, from one browser to another.

Because of the history of confusion and inconsistent implementation surrounding this kind of declaration, in 2011 the HTML Working Group took a decision to make the meta element with http-equiv set to Content-Language non-conforming in HTML. This means that you should no longer use it in HTML5, and therefore, though technically not illegal in other types of HTML, it is best to now not use it anywhere.

HTML5 did, however, make a concession for backwards compatibility. If there is a meta element with http-equiv set to Content-Language in the markup, and if there is no language attribute on the html tag, and if the meta element has a value that is a single language tag, then a browser must use that information to guess at the default language of the text on the page. Having said that, this is only for backwards compatibility, and you really shouldn’t use this approach any more. Simply use a language attribute on the html tag.

Document-internal metadata

One implication of HTML5 dropping the meta element for declaring language is that there is now no obvious way to provide metadata about the document inside the document itself. In theory it would be quite useful for content management systems, translation processes, and the like. This kind of information can be carried by an HTTP header (as we’ll see in the next section), but such systems and processes tend to work on documents that are not sent from a server with an HTTP header, and so in-document metadata would be useful.

Perhaps another approach, such as RDFa, would provide a way of representing such information in the future.

The WHATWG Wiki MetaExtensions page provides an extended list of values that could be used with the meta element’s name value, though none have been formally accepted yet. One such value is dc.language , used to express language information with Dublin Core notation.

It is unclear, however, that this information is ever used by browsers, or to what extent it is used by any other application. The WHATWG page recommends that the lang attribute be used instead. That recommendation is good for declaring the text-processing language, but doesn’t address its possible use for expressing metadata about the page as a whole.

Further reading

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