On long flights, seat choice affects your comfort more than almost any other decision you make while booking.
Window Seat: Uninterrupted Rest
A window seat gives you a wall to lean against for sleeping and means you won’t be disturbed by seatmates getting up. You also get the view during takeoff, landing, and daylight portions of the flight. The downside is being stuck in place if you need the bathroom while others are sleeping.
Aisle Seat: Freedom of Movement
An aisle seat lets you get up whenever you want without disturbing anyone, which matters on long flights where stretching your legs helps with circulation. The tradeoff is more interruptions from other passengers and crew carts passing by, and no wall to rest against.
Which Is Better for Long Flights?
If your priority is uninterrupted sleep on an overnight flight, window wins. If you have a connecting flight, get restless legs, or drink enough water to need frequent bathroom trips, aisle is the more comfortable choice.
Final Thoughts on window seat vs aisle seat
Neither seat is universally better, match your choice to whether sleep or mobility matters more for that specific flight.