Responses under 400ms keep users in flow, above that, engagement drops.
The Principle: Productivity soars when a computer and its users interact at a pace under 400ms, ensuring neither has to wait on the other.
- Respond Within 400ms: Providing system feedback within 400 milliseconds keeps users' attention and directly increases their productivity.
- Manage Perception: Use perceived performance techniques to improve the feeling of response time, even when the actual processing takes longer.
- Animate the Wait: Animation is a powerful way to visually engage users while loading or processing happens in the background, making delays feel intentional rather than broken.
- Progress Bars Build Patience: Progress indicators help make wait times tolerable, regardless of how accurately they reflect the actual time remaining.
- Delay Can Add Value: Purposefully adding a small delay to a process can increase its perceived value and build a sense of trust, even when the process itself takes far less time.