Roger Ebert's website gives a glowing review that closes with this:
A wondrously affecting work, "Pinocchio" becomes a magnum opus for del Toro that channels his interests and beliefs long present in his oeuvre but spun with a luminous new gravitas. It may go against its ethos to deem del Toro's "Pinocchio" an impeccable masterpiece, even if that's an adequate description, but know that if the art of making movies resembles magic, this is one of its greatest incantations.Rolling Stone says,
The movie is beautiful. This take on the Pinocchio puppet reminds us, among other things, that he’s made of wood. He looks and moves and creaks and breaks like wood. He’s got knots for eyes and an entire personality carved into his body by benefit of the fractal patterns in the pine wood used to make him. He’s got the kind of thin awkwardness befitting a puppet, the kind where the head looks too heavy for the body. And yet there’s a real boyishness to him, somehow — here and throughout, with every character, the animators clearly took care to master the expressiveness of the eyes, the natural flow of movement.The Verge calls it "a haunting and beautiful instant classic that will leave you thinking about your mortality." Rotten Tomatoes has a critics consensus score of 97%.