The Swiftness Potion is a buff potion which grants the Swiftnessbuff when consumed. The buff increases maximum movement speed by 25%. This lasts for 8 minutes, but can be canceled at any time by right-clicking the icon (), by selecting the icon and canceling it in the equipment menu (), by double-tapping the buff icon (), or by canceling the buff from the buffs screen (). The effect does not stack with Hermes Boots nor does it affect the speed of mounts.
Whilst the Swiftness buff alone will not boost the player's top running speed whilst wearing any sprinting accessory, it will boost top speed further when running on Asphalt Blocks, and also increases airborne mobility.