The lang global attribute helps define the language of an element: the language that non-editable elements are written in, or the language that the editable elements should be written in by the user. The attribute contains a single “language tag” in the format defined in Tags for Identifying Languages (BCP47).
The default value of lang is unknown, therefore it is recommended to always specify this attribute with the appropriate value.
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If the attribute value is the empty string (lang=""), the language is set to unknown; if the language tag is not valid according to BCP47, it is set to invalid.
Language tag syntax
The full BCP47 syntax is in-depth enough to mark extremely specific language dialects, but most usage is much simpler.
A language tag is made of hyphen-separated language subtags, where each subtag indicates a certain property of the language. The 3 most common subtags are:
- Language subtag
- Required. A 2-or-3-character code that defines the basic language, typically written in all lowercase. For example, the language code for English is
en, and the code for Badeshi isbdz. - Script subtag
- Optional. This subtag defines the writing system used for the language, and is always 4 characters long, with the first letter capitalized. For example, French-in-Braille is
fr-Braiandja-Kanais Japanese written with the Katakana alphabet. If the language is written in a highly typical way, like English in the Latin alphabet, there is no need to use this subtag. - Region subtag
- Optional. This subtag defines a dialect of the base language from a particular location, and is either 2 letters in ALLCAPS matching a country code, or 3 numbers matching a non-country area. For example,
es-ESis for Spanish as spoken in Spain, andes-013is Spanish as spoken in Central America. “International Spanish” would just bees.
The script subtag precedes the region subtag if both are present — ru-Cyrl-BY is Russian, written in the Cyrillic alphabet, as spoken in Belarus.
To find the correct subtag codes for a language, try the Language Subtag Lookup.
Even if the lang attribute is set, it may not be taken into account, as the xml:lang attribute has priority.
For the CSS pseudo-class :lang, two invalid language names are different if their names are different. So while :lang(es) matches both lang="es-ES" and lang="es-419", :lang(xyzzy) would not match lang="xyzzy-Zorp!".
Specifications
| Specification | Status | Comment |
|---|---|---|
| HTML Living Standard The definition of 'lang' in that specification. |
Living Standard | No change from latest snapshot, HTML 5.1 |
| HTML 5.1 The definition of 'lang' in that specification. |
Recommendation | Snapshot of HTML Living Standard, no change from HTML5 |
| HTML5 The definition of 'lang' in that specification. |
Recommendation | Snapshot of HTML Living Standard, behavior with xml:lang and language determination algorithm defined. It also is a true global attribute. |
| HTML 4.01 Specification The definition of 'lang' in that specification. |
Recommendation | Supported on all elements but <applet>, <base>, <basefont>, <br>, <frame>, <frameset>, <iframe>, <param>, and <script>. |
Browser compatibility
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
lang | Chrome Full support Yes | Edge Full support 12 | Firefox Full support Yes | IE Full support Yes | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support Yes | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support