What is a good website for identifying grape leaves online?
Most people use DNA testing or wait for the fruit to appear on the vine (fruit is easy, leaves – not so much). You are probably better off looking up a botanical lab, nursery, extension office and sending them pictures/samples of the vine. There may be a fee. Most of the sites I have seen rarely try to identify by leaf. You might also find some books on “ampelography” at the library or local university.