NoFall is a Minecraft hack that protects the user from fall damage.
Unlike Minecraft's own Feather Falling enchantment, NoFall blocks all fall damage regardless of height and does not require any special armor. NoFall also doesn't change the speed at which the player falls, unlike the Slow Falling effect.
NoFall bypasses the original “AntiCheat” server plugin, but it is blocked by newer anti-cheat plugins such as NoCheat+.
It should be noted that using NoFall while flying with an elytra can sometimes cause the elytra to glitch out and stop in mid-air. This glitch is rare, especially since the Wurst 7.6 update, but it's still noticeable when using the elytra over long distances. It is therefore recommended to turn NoFall off before long-distance flights.