The HTML lang attribute can be used to declare the language of a Web page or a portion of a Web page. This is meant to assist search engines and browsers.
<html lang="en">
...
</html>
Abkhazian- ab
Afar- aa
Afrikaans- af
Albanian- sq
Amharic- am
Arabic- ar
Aragonese- an
Armenian- hy
Assamese- as
Aymara- ay
Azerbaijani- az
Bashkir- ba
Basque- eu
Bengali- (Bangla) bn
Bhutani- dz
Bihari- bh
Bislama- bi
Breton- br
Bulgarian- bg
Burmese- my
Byelorussian- (Belarusian) be
Cambodian- km
Catalan- ca
Chinese- zh
Chinese- (Simplified) zh-Hans
Chinese- (Traditional) zh-Hant
Corsican- co
Croatian- hr
Czech- cs
Danish- da
Dutch- nl
English- en
Esperanto- eo
Estonian- et
Faeroese- fo
Farsi- fa
Fiji- fj
Finnish- fi
French- fr
Frisian- fy
Galician- gl
Gaelic- (Scottish) gd
Gaelic- (Manx) gv
Georgian- ka
German- de
Greek- el
Greenlandic- kl
Guarani- gn
Gujarati- gu
Haitian Creole- ht
Hausa- ha
Hawaiian
Hebrew- he, iw
Hindi- hi
Hungarian- hu
Ibibio
Icelandic- is
Ido- io
Igbo
Indonesian- id, in
Interlingua- ia
Interlingue- ie
Inuktitut- iu
Inupiak- ik
Irish- ga
Italian- it
Japanese- ja
Javanese- jv
Kannada- kn
Kanuri
Kashmiri- ks
Kazakh- kk
Kinyarwanda- (Ruanda) rw
Kirghiz- ky
Kirundi- (Rundi) rn
Konkani
Korean- ko
Kurdish- ku
Laothian- lo
Latin- la
Latvian- (Lettish) lv
Limburgish- ( Limburger) li
Lingala- ln
Lithuanian- lt
Macedonian- mk
Malagasy- mg
Malay- ms
Malayalam- ml
Maltese- mt
Maori- mi
Marathi- mr
Moldavian- mo
Mongolian- mn
Nauru- na
Nepali- ne
Norwegian- no
Occitan- oc
Oriya- or
Oromo- (Afaan Oromo) om
Papiamentu
Pashto- (Pushto) ps
Polish- pl
Portuguese- pt
Punjabi- pa
Quechua- qu
Rhaeto-Romance rm
Romanian- ro
Russian- ru
Sami- (Lappish)
Samoan- sm
Sangro- sg
Sanskrit- sa
Serbian- sr
SerboCroatian- sh
Sesotho- st
Setswana- tn
Shona- sn
Sichuan- Yi ii
Sindhi- sd
Sinhalese- si
Siswati- ss
Slovak- sk
Slovenian- sl
Somali- so
Spanish- es
Sundanese- su
Swahili (Kiswahili)- sw
Swedish- sv
Syriac
Tagalog- tl
Tajik- tg
Tamazight
Tamil- ta
Tatar- tt
Telugu- te
Thai- th
Tibetan- bo
Tigrinya- ti
Tonga- to
Tsonga- ts
Turkish- tr
Turkmen- tk
Twi- tw
Uighur- ug
Ukrainian- uk
Urdu- ur
Uzbek- uz
Venda
Vietnamese- vi
Volapük- vo
Wallon- wa
Welsh- cy
Wolof- wo
Xhosa- xh
Yi
Yiddish- yi, ji
Yoruba- yo
Zulu- zu
In the above code snippet we have defined language codes by giving their codes in the html page