What is ReactJS?

What is ReactJS?

What is the use of ReactJS and why do over 1 million live websites choose to use it?

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ReactJS is an open-source Javascript library that is component-based. The library is run by Facebook and a handful of other companies but the main source of their content comes from individual contributors from around the world. This Javascript library is used to build user-interfaces (UI) that are specifically for single-page applications. Currently, ReactJS has been downloaded 85,378,251 times since the start of 2020, with an average of 7,057,139.46 downloads per week. Considering the download data, ReactJS is currently on the rise and doesn't seem to be slowing down any time soon.

Where did ReactJS come from?

ReactJS was created in 2011, with its flagship application being the foundation of the first Facebook app. Prior to ReactJS developers primarily used jQuery and a few other UI interfaces to create the appropriate framework for their websites. However, frameworks of this nature are usually complicated and hard to explain. Thus, it was much more difficult for new developers and even new members to software development teams to get the hang of the programming structure.
ReactJS is different in that it is component-based. This means it does not make assumptions about the rest of a platform’s technology stack. This makes it possible to develop new features to React without rewriting the existing code. This is new because it separates the systems so that they are not always reacting to the entire program; rather, each component has its own set of reactions. This helps minimize bugs and issues, as well as helping to isolate problems without ripping apart the whole code. Considering Facebook was the intuitive, first-generation parent company for ReactJS and still is, it has always had the advantage of rising in success with its creator.

four developers with laptops working near huge electronic devices like computer screen and laptop

Why Use ReactJS?

There are many different reasons that ReactJS, even nine years after it was first created, is still being downloaded in the millions, on a daily basis. Here is a description of the framework’s best features to explain what ReactJS is used for:

ReactJS Virtual DOM

When websites use pure JavaScript coding, the platform’s DOM object will re-render every time any change is done in any of the HTML elements. For a static website without too many components, this is fine. However, if a software developer is running a dynamic website with apps or a lot of user interaction elements, the rendering cannot keep up and the quality of the website suffers dramatically.

Thankfully, Virtual DOM helps rectify this situation by creating a copy of the DOM. This is called Virtual Dom. This copy is compared with the normal DOM and the only elements that are re-rendered are those which are changed. This system is less invasive and it takes less computing power, which results in faster loading time and mitigates any bugs or rendering issues that may arise.


JSX is the way the ReactJS platform creates templates, instead of using straight HTML. JSX is created to work much like an extension of Javascript, which allows the creating developer to use HTML tags inside the Javascript code. This makes for an easier, smoother, and more comprehensive coding experience.

React Native

Considering ReactJS and React Native are both products of Facebook, (with React Native being created to compliment ReactJS) it isn’t hard to understand that using one will help prime software developers for using the other. Where ReactJS is a website framework and JavaScript Library, React Native is its mobile application counterpart.

round logos of ReactJS, JSX and React Native on grey background

Additionally, ReactJS can render on the server using Node and power mobile apps using React Native. Therefore, they can work together, as well as being two similarly functioning solutions for desktop and mobile-based applications.

Pros and Cons of ReactJs

ReactJS is an explosively powerful JavaScript Library that currently has over 25.4K stars on GitHub and continues to climb. However, that doesn’t mean that everyone is thrilled with all aspects of the ReactJS performance. Here is a list of both pros and cons to ReactJS to help each individual developer decide whether ReactJS will be the best framework for their projects:

Pros of ReactJS

-The Ability to Repeat Code.

Before ReactJS, a developer would have to use straight code, rewriting it over and over again, for different aspects of the same projects (and other projects). However, with ReactJS came the concept of modular code. Modular code is a part of the React JS library that enables developers to use separate modular components to create different aspects of code applications.  Have a look at the example. Here’s the component to describe the look and behavior of the link.

react code example

And now you can use the link component in any part of the application code. Let’s take the social media links for example.

react code example social media

Essentially the implication of modular code is the core of the open-platform and JavaScript library concept; being able to use one portion of code for many different applications. In addition to helping developers learn and share their experiences, modular code helps take the monotony out of coding, which saves software developers a lot of time (and money).

- Available in Different Languages.

Code is not the only language that is customizable throughout the ReactJS library. Since JavaScript is a global system, it only seems right that the website and framework itself is available in many different languages. In addition to English and Spanish,  here are the current languages that the framework supports:

  • Arabic
  • Azerbaijani
  • French
  • Italian
  • Japanese
  • Korean
  • Mongolian
  • Polish
  • Portuguese (Brazil)
  • Russian
  • Turkish
  • Ukrainian
  • Simplified Chinese
  • Traditional Chinese

However, even this selection of languages is not the end of the platform’s future communication plans. There are over two-dozen other languages of content that are currently being produced or are actively seeking contributors.

French, Ukrainian, Russian, Italian, Chinese and Polish flags on white background

- ReactJS is Updated Frequently.

ReactJS is updated frequently, with a talented, global team helping to make it as universally useful as possible. Therefore, a developer of any level of experience can be sure they are working with the most updated system ReactJS has to offer. This is important, especially for long-running successful frameworks, such as ReactJS and React Native because a constant update is better on the system. Instead of having a few major updates, there are many smaller updates, which help developers manage the changes and debug their platforms in a manageable way.

Cons of ReactJS

- ReactJS is a JavaScript Library First.

ReactJS is a JavaScript library, but it is also a framework. Generally, this is not a bad thing. In fact, it is usually a beneficial attribute. However, since ReactJS primarily functions as a JavaScript library, it is not a complete framework. This means that often, other JavaScript Libraries need to be implemented to complete an application. To be fair, though, even full-fledged frameworks are better when third-party integrations are easily added and executed within a program. So, this likely won’t be a deal-breaker for most software developers.

- SEO Issues.

Remembering that ReactJS is a digital child of Facebook, the fact that many find the framework’s extra SEO steps annoying is ironic. While it is not bad at SEO, ReactJS certainly isn’t the best. In 2014, Google webmasters confirmed that the search engine’s crawlers cannot properly index dynamic content. Since ReactJS is built around the idea of adding dynamic content to a website, this is disappointing. Now, that doesn't mean that a website with the ReactJS framework will not be indexed. But, it does mean that there are a few extra tests to make sure Google (and other search engines) crawlers notice the site.

- There is a Learning Curve.

ReactJS has a lot going on, between the JavaScript Library and the framework components, there are a lot of moving parts to the platform. This means that the framework needs to be updated frequently and its open-source nature makes it a consistently incomplete package. Plus, the names and exact functions of the tools are frequently updated. While this is not really a big deal for experienced developers and ultimately the updates are only improving the system, the constant change and progression can make for a difficult learning curve.

What Types of Projects is ReactJS Ideal For?

logos of ReactJS, Instagram, Netflix, Facebook, Dropbox, AirBnb on white backgorund

ReactJS is perfect for development in various industries, from real estate web development to blockchain development. It is used to create and maintain thousands of popular websites and social networking platforms. Here is a list of some of the most famous:

  • Facebook (Obviously)
  • Reddit
  • Airbnb
  • Instagram
  • DropBox
  • Tesla
  • Netflix
  • PayPal

Basically, this list of just the top-rated websites that use ReactJS is overwhelming. When the average person looks at this list, alone, though, they notice the range of seemingly unrelated websites and platforms that use ReactJS. Indeed, this is an amazing feat, considering the list ranges from banking applications to social networks, and from personal BnBs to cloud storage providers. However, what a developer sees when they look at this list is even more enlightening. From this list, developers can get a good picture of exactly what the single-page application framework can accomplish.

To close, ReactJS is an awesome JavaScript library and framework that continues to revolutionize UI software integration. Software Developers all over the globe are pleased with the diversity that ReactJS allows. Plus, with the additional success of React Native and the easy crossover options, developers have a whole new world of innovation and possibilities to explore. And if you need to hire developers with extensive knowledge of ReactJS, don't hesitate to visit the link above.

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What is ReactJS?