If you're ever unsure, there are a few other ways to figure out what model the plane you're flying on is.
Ask a crew member. If they work on the plane, they should know.
Check the app where you booked your flight; it should say what type of model it is.
Lastly, check the safety card in front of your seat. It will say what model it is on the front page, down to the slightest variant (for example, a 747-400 vs a 747-8)