React Performance

Find out what is actually slow before optimising, then use memo, useMemo, useCallback and list virtualisation deliberately rather than by reflex.

Level

Advanced

Chapters

4

Exercises

1

Reading time

18 min

What you will cover

1. 1. Measure Before OptimisingWhy most memoisation is wasted, and how to find the real problem.
2. 2. memo and Referential EqualityHow React.memo works, and the reason it so often does nothing.
3. 3. useMemo and useCallbackWhat each one caches, when it pays off, and what it costs.
4. 4. Rendering Large ListsThe one optimisation that reliably matters, plus splitting work at the bundle level.

Up next after this one: Suspense and Transitions