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Perceived performance 1:07
A 67-second explainer of Perceived performance, narrated over the same demo you can try yourself.
Try the interactive Perceived performance demo
What this video covers
Perceived performance is how fast an interface feels, as opposed to how fast it actually is. By responding instantly to input, showing progress, and assuming success before the server confirms, you can make a product feel quick even when the underlying work takes the same time - because what people judge is the experience of waiting, not the milliseconds.
Both versions hit the server for exactly the same time - but the optimistic one responded the instant you acted, so it felt immediate, while the naive one made you wait and felt sluggish. Same real speed, very different felt speed. That's perceived performance: judged by the experience of waiting, not the clock - which is why responding instantly and showing the result early so often beats chasing raw milliseconds.
