It is a classic from the Irish poet that comes alive. There is `some' artistic license, but I figure that you have it in every movie adaptation from books (it's not a documentary). Aside from that license, the film follows closely the book, especially when watching other, later movie adaptation of this book.
Book/film differences in short: Sybil is here a gifted dance-hall singer and not an actress, which necessitates changing the reason for Dorian to break up with here. The novel has no reference to Dorian being painted with an Egyptian goddess shaped like a cat who could grant his wish, as the film has. Henry's final speech to Dorian Gray in the novel about the soul being non-material but corruptible is one he claims to have heard from a street-preacher. In the film, Dorian hears these words himself from a street-preacher. Dorian's final marriage before his death is to a parson's daughter in the novel; In the film, it is to Basil Hallward's niece, Gladys, who had a childhood crush on Dorian.
Besides that, the film is one I loved. For those who like Dorian, go see it.