DeepL accepts the following languages

read more about supported languages here

source languages

bgBulgarian
csCzech
daDanish
deGerman
elGreek
enEnglish
esSpanish
etEstonian
fiFinnish
frFrench
huHungarian
idIndonesian
itItalian
jaJapanese
koKorean
ltLithuanian
lvLatvian
nbNorwegian
nlDutch
plPolish
ptPortuguese
roRomanian
ruRussian
skSlovak
slSlovenian
svSwedish
trTurkish
ukUkrainian
zhChinese

target languages

bgBulgarian formal: false
csCzech formal: false
daDanish formal: false
deGerman formal: true
elGreek formal: false
en-GBEnglish (British) formal: false
en-USEnglish (American) formal: false
esSpanish formal: true
etEstonian formal: false
fiFinnish formal: false
frFrench formal: true
huHungarian formal: false
idIndonesian formal: false
itItalian formal: true
jaJapanese formal: true
koKorean formal: false
ltLithuanian formal: false
lvLatvian formal: false
nbNorwegian formal: false
nlDutch formal: true
plPolish formal: true
pt-BRPortuguese (Brazilian) formal: true
pt-PTPortuguese (European) formal: true
roRomanian formal: false
ruRussian formal: true
skSlovak formal: false
slSlovenian formal: false
svSwedish formal: false
trTurkish formal: false
ukUkrainian formal: false
zhChinese (simplified) formal: false