What block am I testing this time? The change [ v] by [] block! It will run every second. The project will graph the time lost due to this block. It will meow when the total time lost reaches one second. The "lag" time is usually 23 milliseconds, but can change quite a bit if you move your mouse, click see inside, click the sprite, or even scroll! Interestingly, the lag tends to be more consistent on mobile than on computer. In fact, it even seems to be the same between Scratch and Tur***arp.