In brief: Website speed describes how quickly a page loads, renders, and responds to input. Assess it on real devices and networks, not just one lab number.
How I use Website speed in practice
I begin with the visitor’s task, not a designer’s idea. I follow the journey on a small phone, with a keyboard, and on a slow connection, then watch where people hesitate or make errors. Every change needs a reason, a measurable signal, and the smallest possible intervention so its impact can be identified.
What to watch out for
The commonest mistake is changing several things at once without a baseline. Then it is impossible to know whether speed helped. A metric without observation cannot explain why people hesitate or leave.
Questions for decisions
- What task should the person complete on the page?
- Where might they hesitate, make an error, or lose context?
- Does it work on mobile, with a keyboard, and on a slow network?
- What signal will show that the change helped?