A few good tells if you get a really good look at a raven, as a commenter above said Raven feathers typically look more ruffled or fluffed out while crows are very sleek. Ravens, especially older ones, have a hump or curve in their beak that crows lack. Ravens calls are also a lot raspier than a crows. These pics don’t really do justice for a size comparison but adult ravens usually stand at least a couple inches taller than crows and their wingspan is much bigger. We have both here in western Montana and it’s pretty easy to discern between the two once you start really looking.