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).

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 is bdz.
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-Brail and ja-Kana is 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-ES is for Spanish as spoken in Spain, and es-013 is Spanish as spoken in Central America. “International Spanish” would just be es.

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!".


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
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

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes Yes Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes Yes Yes Yes Yes

See also

Document Tags and Contributors

Contributors to this page: Tigt, fscholz, xfq, jonny5, arosamiran, adrianheine, Sebastianz, rayhatfield, teoli
Last updated by: Tigt,