There are a few key differences between muzzle brakes and flash hiders. First, muzzle brakes vent gases to the side to reduce recoil, while flash hiders simply disperse the gases to make it more difficult for an opponent to see the shooter's location. Second, most muzzle brakes have holes drilled into them specifically to release gas, while flash hiders do not typically have any openings. Finally, because of the way they work, muzzle brakes will often increase the noise level when fired, while flash hiders will not.