If your React app exhibits a performance issue, such as sluggish rendering or slow-loading elements, you can use the Profiler tool included within the React Developer Tools browser plugin. The Profiler is a tool for finding and diagnosing performance issues in your code. It works up-front by capturing information about how long the app takes to load when you open it in your browser. It also provides information about how long each element takes to load and how much memory each element takes up.
The first thing to do if a React app exhibits a performance issue is to use the Profiler tool included within the React Developer Tools browser plugin. This tool will let you know what’s going on under the hood of your app as soon as possible so that you can fix it right away!
A component that is rendered without a reason can be one of the most frequent problems in React apps. It’s quite common to see a component, which gets rendered multiple times within the same render method. This happens when components are reused in different places within your application, or when you use them to wrap other components. If you don’t have any optimizations in place, this can lead to many unnecessary re-renders.
It’s also often the case that these components are not updated properly and end up being used by the user as is – even if they haven’t changed. That’s why it’s important to find out why rendering happens and fix those issues as soon as possible.
React offers two tools that are useful in these circumstances:
React. memo: This prevents unnecessary re-rendering of function components. A higher order component is react.memo. You can sometimes wrap a component in a call to React.memo for a performance benefit by memoizing the result if it produces the same result given the same props. This indicates that React will reuse the most recent rendered result and forego rendering the component.
PureComponent: We think it’s important to know how much time and energy is spent on rendering class components in your application. That’s why we’ve added the ability to “prevent re-rendering of class components” in PureComponent. This feature will allow you to stop class components from unnecessarily being rendered again, which can save you time and energy.
Both of these tools rely on a quick check of the props that were supplied into the component; if the props have not changed, the component won’t re-render. Both tools can have a negative performance impact if used improperly, even though they are both extremely useful. This is because the shallow comparison imposes a further performance penalty.
Performance can be compared before and after utilizing these tools by using the React Profiler, ensuring that any changes made truly enhance performance.
Conclusion :
React was designed to work well, even on slow connections. In a lot of cases, you can make your application faster by following the steps described above. Of course, the fewer number of components and views you have, the better experience you will provide your users.