Which file extension is used to save Kotlin files. Q & A › Which file extension is used to save Kotlin files. 0 Vote Up Vote Down Admin Staff asked 4 years ago Which file extension is used to save Kotlin files. a).java b).kot c).kt or .kts d).andriod Share this:TwitterFacebookWhatsAppPinterestLike this:Like Loading... 1 Answers 0 Vote Up Vote Down Admin Staff answered 4 years ago c).kt or .kts Share this:TwitterFacebookWhatsAppPinterestLike this:Like Loading...