Performance optimization of an application designed using React is a vital factor to consider, especially if you hope to increase the speed of the solution. Here you’ll find a few easy-to-implement techniques to take the performance standards of your app to the next level.

1. How To Increase The UI
Performance Of Apps
Designed Using React?

2. Table of Contents
● 1) How it works?
● 1. PureComponent
● 2. ShouldComponentUpdate
● 3. UseEffect
● 4. List virtualization or windowing
● 5. Memoize using React.memo
● 6. Caching the function
● 7. Suspense, Concurrent mode, and useDeferredValue
● 8. Lazy loading and code splitting
● 9. Throttle data fetching or debouncing
● 10. Profiling
● 2) Endnote

3. Introduction
Performance optimization of an application designed using React is a
vital factor to consider, especially if you hope to increase the speed of
the solution. Here you’ll find a few easy-to-implement techniques to
take the performance standards of your app to the next level.
No matter how many developers you speak to, everyone will say the
same thing – when it comes to building a web application,
optimization trumps everything else. By using a virtual DOM, a top
rated react development company can enhance the efficiency at
which it updates the user interface of the solution.

4. How it works?
Every application designed using React has multiple components
placed in the formation of a tree. These components are nothing but
the functions rendering the user interface according to the props
received. As soon as there’s an alteration in data, React will compute
the differences between the new UI and the existing one. After that,
it’ll proceed to apply the changes concerning the UI only to the
original UI on the web browser. This constant “comparing and
rendering” is often the issue associated with the performance-related
problems seen in React applications.
React mostly works by sustaining the in-memory model of a view, also
called the virtual DOM. It’s what React uses to ascertain when to
update the existing DOM and whether it update it at all or not.
Tinkering with the existing DOM can be expensive. Naturally, when it
comes to improving performance, the top rated react development
company has to ensure that the DOM changes only when there’s no
other option.
.

5. If the component needs only a simple and shallow prop comparison
and state to ascertain go/no-go on the decision about the rendering,
developers can extend the base class called the “PureComponent”
like “class MyComponent extends React.PureComponent.” In doing
so, if React doesn’t detect any changes in the props and state while
running the shallow comparison, “render()” won’t do anything. The
“PureComponent” describes a lack of the side effects in the
component. It’s perfectly pure in terms of causing changes to the
output only against the changes in the property or state.
1. Pure Component

6. While writing components depending on class, developers can
override the lifecycle method called the
“shouldComponentUpdate().” The objective of this method is to
declare whether the component needs re-rendering or not.
Rendering can be an expensive part associated with the lifecycle
during reiteration. It’s precisely where the original DOM gets
updated. React will render only if there’s a change in the state or
props. Developers can choose to skip this procedure as well and
avoid calling the render entirely.
2. Should Component Update

7. The two guidelines discussed above work only for components based on
class. The providers of react app development services achieve the same
results using the features of functional components, such as the “useEffect”
hook and “memo.” “useEffect” is quite similar to the
“shouldComponentUpdate” explained above. It facilitates running potentially
costly code, but only if there’s a change in the variable.
3. UseEffect

8. Here’s a technique that works with both class and functional components.
Developers describe it as “windowing” or “list virtualization.” If developers have
massive datasets to showcase through lists, then they usually resort to data
“windowing.” In simple words, they simply load and display just a small section
of the data at any moment. It will prevent massive pieces of data from forcing
the UI to come to a halt.
4. List virtualization or windowing

9. There’s another trick that the best providers of react app development services
often rely on while using functional components. It’s called “React.memo,”
which is a high-order component. It basically means that this component
wraps around the one used in the app and adds extra behavioral features to it.
In this instance, “memo” facilitates the functional component to cache the
results if they’re similar to the same props. A developer uses the word
“memoize” to describe this action. During normal circumstances, functional
components will never cease to render, even when the props are inconsistent.
To replicate the way the “PureComponent” behaves in comparison to “props
only,” developers wrap the functional component in a way only they can
explain. It will check for alteration in the props, but not in the state. If the
“props.quote” doesn’t change, the component won’t re-render.
5. Memoize using React.memo

10. If developers have to work with pricey function calls, they often consider
caching them. They do it in the form of a memoized cache described above.
However, the function characteristics will dictate and guide the possibilities of
caching. In specific instances, caching functions can avoid fetching data calls
entirely
6. Caching the function

11. React 16 introduced a new feature that also changed the system entirely. It’s
the concurrent mode. Unfortunately, the method of using this mode is quite
complicated. Naturally, it won’t be possible to explain what it does and how it
does so in this write-up. You only need to know that an experienced developer
can use the “Suspense” component to improve the actual, as well as
perceived experience of your web app beyond your expectations. In short, the
concurrent mode will ensure the rendering and fetching take place
simultaneously. Apart from the “Suspense” component that defines the
appropriate data fetching areas, React 16 has the power to disclose other
unique and ingenious strategies, such as using the “useDeferredValue.” It can
enhance the way specific features work, such as the auto-suggest system. It
will also get rid of issues that contribute to UI problems, including stuttering
while typing.
7. Suspense, Concurrent mode, and use
DeferredValue

12. The best developers always keep a bag of surprises hidden in their pockets.
They draw from it now to enhance the user interface of an app built using
React. Another one of those tricks is the lazy loading of bundled code.
Through this technique, developers ensure the app loads data only when it
becomes absolutely necessary. “React.lazy()” is a function that came with
React 16.6. This function facilitates a more natural use of the code splitting
method. It just means that the developer can use regular component syntaxes
and still acquire the semantics of lazy loading. The versions of React that
came before React 16.6 had an extremely cumbersome and annoying
code-splitting system. Nevertheless, this issue never affected its effectiveness.
Development agencies using older versions of React can offer significant
improvements for big codebases.
8. Lazy loading and code splitting

13. In specific cases where developers resort to the “throttle” or “debounce”
functions, the concurrent mode of React described above can handle it much
more proficiently. If the concurrent mode is unavailable to the developers you
hire, they can use these two functions to avoid situations where using naïve
strategies often end up in excessive chattering during data fetching. For
example, in the instance of data fetching while a user types something, firing
off a request against every keystroke will result in performance surges.
Developers can remove the problem entirely by using the “debounce” or
“throttle” functions. Nevertheless, the concurrent mode is much better than
these two functions. That’s why it’s better for you to look for a development
agency where the concurrent mode is available to the developers on their
React platform.
9. Throttle data fetching or debouncing

14. Now that you’ve seen several techniques used by developers to enhance the
UI performance of an app created using React, it’s time to understand the
importance of application profiling. Profiling will uncover all bottlenecks and
even verify whether the changes implemented are effective at all or not. Web
browsers, such as Firefox and Google Chrome come with an in-built profiler.
Developers can use these profilers to do their jobs. The dev mode of React will
allow them to see the particular components in use when they check the
profiler. It’s also useful in examining the network tab and pinpointing all slow
backend calls. Developers can’t fix these areas in JavaScript, but they can do
it if they reach the backend. The newest versions of React, including 16.5 and
other versions come with a DevTools Profiler. It possesses significantly more
detailed capabilities. It can connect with the latest concurrent mode features.
10. Profiling

15. As a business owner, it’s not your job to understand the nitty-gritty of the
technical matters described above. However, you can use the information as a
reference point that you can use to interview potential candidates. After all,
building an application using react platform isn’t easy, especially if you want an
exceptionally fast UI.
Endnote

16. THANKS
Original Source :
https://www.moontechnolabs.com/blog/how-to-increase-the-ui-perfo
rmance-of-apps-designed-using-react/