React · Middle · Question 66 of 75

What is the `<Profiler>` component for?

<Profiler id="Sidebar" onRender={(id, phase, actualDuration) => log(id, actualDuration)}>
  <Sidebar />
</Profiler>

✓Correct answer: Measuring how often a subtree renders and how long it takes, programmatically
2Showing a loading indicator
3Logging errors from the subtree

Explanation

It adds some overhead and is disabled in production builds by default. The DevTools Profiler is usually enough for manual investigation.

Further reading

react.dev: <Profiler> ↗

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