The following table lists the two-letter language codes from the ISO 639 international standard.

In applications, these two-letter codes are represented by case-insensitive ASCII character codes. In the World Wide Web, language codes are used to select between special native language symbols, such as punctuation marks, currency, numerical notation (e.g. commas instead of periods as the decimal separator), text direction (left to right or right to left), and so on.

aa: Afar
ab: Abkhazian
af: Afrikaans
am: Amharic
ar: Arabic
as: Assamese
ay: Aymara
az: Azerbaijani
ba: Bashkir
be: Byelorussian
bg: Bulgarian
bh: Bihari
bi: Bislama
bn: Bengali; Bangla
bo: Tibetan
br: Breton
ca: Catalan
co: Corsican
cs: Czech
cy: Welsh
da: Danish
de: German
dz: Bhutani
el: Greek
en: English
eo: Esperanto
es: Spanish
et: Estonian
eu: Basque
fa: Persian
fi: Finnish
fj: Fiji
fo: Faeroese
fr: French
fy: Frisian
ga: Irish

gd: Scots, Gaelic
gl: Galician
gn: Guarani
gu: Gujarati
ha: Hausa
he: Hebrew
hi: Hindi
hr: Croatian
hu: Hungarian
hy: Armenian
ia: Interlingua
id: Indonesian
ie: Interlingue
ik: Inupiak
in: Indonesian
is: Icelandic
it: Italian
iu: Inuktitut
iw: Hebrew (obsolete)
ja: Japanese
ji: Yiddish (obsolete)
jw: Javanese
ka: Georgian
kk: Kazakh
kl: Greenlandic
km: Cambodian
kn: Kannada
ko: Korean
ks: Kashmiri
ku: Kurdish
ky: Kirghiz
la: Latin
ln: Lingala
lo: Laothian
lt: Lithuanian
lv: Latvian, Lettish

mg: Malagasy
mi: Maori
mk: Macedonian
ml: Malayalam
mn: Mongolian
mo: Moldavian
mr: Marathi
ms: Malay
mt: Maltese
my: Burmese
na: Nauru
ne: Nepali
nl: Dutch
no: Norwegian
oc: Occitan
om: (Afan), Oromo
or: Oriya
pa: Punjabi
pl: Polish
ps: Pashto, Pushto
pt: Portuguese
qu: Quechua
rm: Rhaeto-Romance
rn: Kirundi
ro: Romanian
ru: Russian
rw: Kinyarwanda
sa: Sanskrit
sd: Sindhi
sg: Sangro
sh: Serbo-Croatian
si: Singhalese
sk: Slovak
sl: Slovenian
sm: Samoan
sn: Shona

so: Somali
sq: Albanian
sr: Serbian
ss: Siswati
st: Sesotho
su: Sundanese
sv: Swedish
sw: Swahili
ta: Tamil
te: Tegulu
tg: Tajik
th: Thai
ti: Tigrinya
tk: Turkmen
tl: Tagalog
tn: Setswana
to: Tonga
tr: Turkish
ts: Tsonga
tt: Tatar
tw: Twi
ug: Uigur
uk: Ukrainian
ur: Urdu
uz: Uzbek
vi: Vietnamese
vo: Volapuk
wo: Wolof
xh: Xhosa
y: Yiddish
yo:  Yoruba
za: Zuang
zh: Chinese
zu: Zulu