10 Best JavaScript Frameworks You Should Know

According to the 2021 StackOverflow developer survey, JavaScript is the most commonly used language for the 8th year straight with 67.7%. The major reason for its popularity is the fact that JavaScript is versatile and can be used for both frontend and backend development as well as for testing websites or web applications.

While researching JavaScript, you might come across various JavaScript frameworks, each with their own advantages and usage. With so many choices for the JavaScript frameworks for frontend, backend development, or even testing it’s difficult to choose the best JavaScript framework for your requirements.

In this article with the help of The State of Frontend 2020 Report among more than 4,500 professional front-end developers, who responded to the survey, we have come up with a list of the best JavaScript frameworks for frontend, backend, and for testing which might help you on choosing the right JavaScript framework for your project.

1. The State Of Javascript In 2021

Nowadays, JavaScript is one of the all-purpose and most popular programming languages – meaning it runs across the entire software stack. JavaScript isn’t only used to create websites. It can also be used to build browser-based games and, with the help of certain frameworks, mobile apps for different operating systems. The creation of new libraries and frameworks is also making it possible to build backend programs with the language, such as web apps and server apps.

Since its creation in 1995, JavaScript is pretty much everywhere on the web—and that’s not likely to change any time soon. As mentioned, it’s the most commonly used programming language for the eight year in a row. As long as people are interacting with the web, you can assume that JavaScript is highly relevant.

2. What Are Javascript Frameworks?

In the world of development, the term ‘JavaScript framework’ refers to a JavaScript library that renders data-driven and interactive interfaces. These frameworks are designed to help supply data to the users when they trigger an interaction using an application or interface. The JavaScript libraries or frameworks differ from each other. But, their end purpose is the same – to show new data when users initiate a request for interaction.

JavaScript Frameworks Are:

• Efficient: You can develop high-end mobile and web applications and interfaces over a few weeks or even days. All thanks to its well-structured prebuilt modules and functions!
• Safe: All popularly used javascript frameworks feature firm security arrangements. Several large communities where developers, testers, and users interact, also support these frameworks.
• Cost-Effective: Most of the JavaScript frameworks are open-source and free to use. They help developers build custom apps faster and easily, at a significantly lower price.

Can you create web applications without using JavaScript frameworks?

You definitely can. However, the development will not be as easy and as problem-free as with FWs. Auto-completion and quality control of your code make the coding process a lot easier, even for experienced programmers.

3. What Makes Frameworks Different From Libraries?

Both JavaScript Frameworks and libraries comprise a group of codes that you can use to build something or solve a problem. The fundamental difference between these two is how you build the structure.

Inversion Of Control

When you’re trying to define framework in the context of library vs framework, think of it like this: when you use JS frameworks the process is more holistic—a framework doesn’t just offer an individual solution to a coding problem, it provides a structure that organizes the parts of your site where the framework is implemented.

This structure comes via page templates with areas set aside for code from the framework’s libraries.

The upside to using JavaScript frameworks is the overall efficiency and organization that they bring to a project—your code will be neatly structured, and the framework will provide readymade solutions for common coding problems.

On the other hand, all of that structure can be the downside of working with a framework—any JavaScript code you write on top of JS frameworks needs to follow rules and conventions specific to the framework, limiting the freedom you have when coding entirely by hand.

When you use a library, you are in control. You can call for the library wherever you feel like.

In other words, you are in charge when you use a JavaScript library. When you use frameworks, the framework usually is.

jQuery And JavaScript Libraries

JavaScript libraries like jQuery are used by plugging library code into the rest of your site’s code when needed.

If you want to use a jQuery template for an autocomplete feature, for instance, you would insert the appropriate jQuery code, which then retrieves the feature from the jQuery library and displays it on your user’s web browser.

In other words, when a front-end developer uses a library like jQuery, the developer is using jQuery code to “call” the jQuery library, which then provides the requested content.

jQuery is one of the most popular JavaScript libraries that remains popular to date. With jQuery, you can compile together multiple lines of code and convert them into single code lines that are easier to use.

No wonder that top tech brands like Google, Netflix, and IBM on the web still use jQuery.

jQuery contains the following elements.

• CSS manipulation
• HTML / DOM manipulation
• AJAX
• Utilities
• HTML event methods
• Effects and animation

jQuery supports a lot of common browsers including Firefox, Chrome, Safari, Internet Explorer, Android, and iOS.

There are two functionalities commonly performed by jQuery:

• Static utility functions
• Object methods

With those limitations in mind, does using JavaScript frameworks mean the framework structure has to be applied to your entire site?

It depends.

While some frameworks are designed to live underneath all of your site or web app’s code, other frameworks allow for incremental use.

This means you can apply the framework to as much or as little of your website or web app as you want. As more frameworks have adopted this incremental model, JS frameworks have become an increasingly flexible way to provide structure when appropriate, while still giving front-end developers the freedom to hand-code when necessary.

4. Which JS Framework Should You Choose For Your Project?

One of the confusing things about JS frameworks is that there isn’t one be-all, end-all JS framework to learn and use. At any given time there are a handful of widely-used popular frameworks reflecting the latest JS trends and innovations. Since there are many, one cannot clearly say this is good, and that is not. It all depends on your requirement and the below four factors.

Choose the one that your team knows and is comfortable with

This is the prime consideration when you choose JavaScript Frameworks. It might be absolutely stunning, but if your team has no idea how to work on it, it will not be of any use.

Three of the most common Frameworks that most developers are familiar with are Angular, Vue, and React. These can be tweaked to match most requirements.

If most of your team members have not used a particular Framework, it makes sense to avoid it, as it is going to take time to learn the nuances of the same.

Choose the one that’s most compatible with your backend

What is your back-end team working with? If the backend team works on Java, then make sure you pick a Framework that closely matches and is compatible with Java. In this case, Angular framework matches closely to Java.

If the back-end and the front-end developers work on completely different languages, then coordinating is going to be a major challenge.

Choose one with the right size and performance

Some Frameworks may be super advanced in their features but may get really heavy to implement. If the app or the website you build is very complicated with lots of layers, then it makes sense to invest in a large JavaScript Framework. However, if you are building a simpler system, then pick up smaller Frameworks like Vue and React.

Make sure you develop a balance between performance and Framework size to get the best efficiency.

Choose one with the right level of complexity

Some developers work on really complex apps and websites that come with hundreds of sub-pages, functionalities, and features. In such a case, pick up a Framework like Angular that can handle complexities like a pro.

Picking up a lighter Framework and trying to build a complex app is going to cause multiple problems in the future.

5. 10 Best JavaScript Frameworks You should Know

JavaScript (JS) frameworks are preferred platforms for building a dynamic modern application, real-time chat, eCommerce, inventory, processing, and much more.

Let’s explore some of the best JS frameworks available in the markets for web application development.

Popular front-end JavaScript frameworks

JavaScript has been widely used for front end development for almost 2 decades. Popular frameworks such as React, Vue and Angular have gained a massive legion of followers while few new competitors have been gaining ground recently to challenge the big 3. Here are the top 4 javascript frameworks of 2021 for front-end.

#1 Popular front-end JavaScript frameworks – React.js

The first place in our best JavaScript framework for 2021 rankings in the front-end category belongs to React.js. React.js is an open-source front end JavaScript library (not a full-fledged framework) that was created by a team of Facebook developers led by Jordan Walke back in 2011 and became open source in June 2013. The initial prototype was dubbed “FaxJS” and was first experimented in Facebook’s Newsfeed. React can be considered one of the biggest influential disruptors in the web development domain that delivered a real breakthrough shaping web applications that we see today.

React introduced a component-based, functional, and declarative programming style for creating interactive user interfaces for mainly single-page web applications. React delivers blazing-fast rendering by making use of ‘Virtual DOM’ that renders only those components that have changed instead of rendering the whole page. Another key feature of React is the use of simpler JSX syntax instead of JavaScript.

Although React presents a slightly steeper learning curve than other best front end JavaScript frameworks in this list, React is supported by a huge developer community, bountiful learning resources, and a massive industry adoption in every corner of the world.

React has consistently topped popularity charts across the board for front end JavaScript framework, be it Stack overflow Developer Survey or the State OF JS Survey. React has consistently won the crown as the favorite front end JavaScript framework. World’s biggest companies and brands like Airbnb, Facebook, Instagram, Netflix, Twitter, WhatsApp, and many others have been built using React. It wouldn’t be wrong to assume that React.js is arguably the best JavaScript framework around.

Pros of using React

• Reusable components – React’s component-based approach helps developers to import or reuse UI components without breaking a sweat insteading of coding them from scratch.
• Easy integration – React allows easy integration with other front-end and back-end frameworks like the popular PHP framework Laravel to work in tandem without a hitch.
• One Direction Data flow – One greatest fundamental difference between React and angular 1 was that React was based on a downward One directional data flow architecture rather than a 2-way data binding adopted by Angular. This ensured that a child element cannot affect the parent making the code more stable and less prone to errors.
• Simpler syntax – React uses JSX JavaScript extension instead of usual JavaScript which is a HTML like syntax that makes the code easier to read, understand and maintain.
• Virtual DOM – React creates a virtual representation or a copy of DOM called Virtual DOM or vDOM. React compares the virtual DOM to the real DOM to only render components that have changed instead of rendering the whole page. This is the key behind React’s blazing fast performance.
• SEO – After many improvements, React is one of the most SEO friendly front end frameworks that facilitates page crawling. Traditional JavaScript frameworks that rendered content dynamically were notorious for their poor SEO performance and incompatibility with search engine crawlers.
• Continuous Improvement – React is in a state of constant evolution and improvement adding key new features like Hooks, Fiber, Concurrent Mode, Suspense etc for reducing boilerplate code, improving concurrency and fast rendering and boosting performance making it a strong contender as the best front end JavaScript framework.
• Rich Community Support – React is backed by a massive Developer Community with almost 1.6k contributors on Github and a wide array of learning resources, tutorials and help guides readily available to anyone starting out. Also do not forget React is backed by one of the largest and most powerful companies in the world – Facebook.

Cons of using React

• Although JSX is a simpler syntax that is easier to read and comprehend, it might present an additional learning barrier to new developers.
• Many developers might feel that React has a much steeper curve and bloated complexity when compared to key rival framework Vue,js or any other frontend JavaScript framework.
• React is often plagued with complaints about poor documentation that cannot catch up with new releases and features forcing developers .
• React only deals with the View Layer of the MVC Model leaving out no other option but to rely on other technologies to deal with Model and Controller Layers.
• React is evolving and changing at a very fast pace requiring developers to play catch up and reskill themselves which can be exhausting and difficult to cope up with. Developers often find themselves stuck in a constant learning cycle which keeps rendering their previous knowledge useless or defunct.

Prominent websites built with React

Airbnb, Asana, BBC, Cloudflare, Codecademy, Dropbox, Facebook, Github, Imgur, Instagram, Medium, Netflix, OkCupid, Paypal, Periscope, Pinterest, Product Hunt, Reddit, Salesforce, Scribd, Shopify, Slack, Snapchat, Squarespace, Tesla, The New York times, Typeform, Twitter, Uber, Udemy, WhatsApp, Zendesk.

Relate: Hire Top React Developers

#2 Popular front-end JavaScript frameworks – Angular.js

The 2nd place in our list of best JavaScript frameworks of 2021 in the front-end category goes to Angular.js. Angular is an open-source typescript based framework by Google used to build client-side single-page web applications. Angular was created by Google’s engineers Misko Hevery and Adam Abrons in 2010 named AngularJS (or Angular 1). AngularJS achieved widespread acclaim and was poised to reign supreme but the emergence of React pushed it into oblivion exposing its grave shortcomings. As a result, AngularJS went through a complete and total rewrite from the ground up and Angular 2 (or just Angular) was released in its place in 2016.

AngularJS(Angular 1) took inspiration from React and made drastic changes, the biggest of which was the shift from M-V-W architecture (Model-View-Whatever) to component-based architecture like React. Today Angular is one of the most secure front end JavaScript frameworks for building enterprise-scale applications out of the box. More than a million websites are using Angular including Google, Forbes, IBM, Microsoft among others.

Pros of using Angular

• Component Based Architecture – After ditching MVW(model-view-whatever) architecture, Angular 2 and beyond adopted a strictly component-based architecture that facilitates reusability. Components can be used over and over again throughout the app. It also enhances code readability and ease of maintenance.
• Server performance – Angular supports out of the box caching and tons of features to ensure fast server performance.
• MVC – Model View Controller in angular establishes key features like scopes and data binding. It also ensures UI and App logic are isolated from each other.
• 2-way data binding – One key feature of Angular is 2-way data binding which forms a link between the Model layer and View layer in such a way that each one of them reflects a change in another. However, other rival frameworks have adopted a one-way data-binding for simplicity.
• Ideal for building Enterprise scale web applications.
• Third-party integrations – Angular offers a rich collection of third party integrations to further enhance their web application.
• Massive Community Support – Angular is blessed with backing from Google and a huge developer community amassing over 1.1k contributors on GitHub. Angular also has great documentation coupled with a huge library of resources and community support.

Cons of using Angular

• Typescript – In order to use Angular you are obliged to use Typescript which does offer a lot of advantages but still poses a big learning challenge to new developers to surmount. Typescript is a big barrier to entry and explains why angular has struggled against both React and Vue.
• Heavy and Bloated – compared to lightweight alternatives like React JS and Vue JS, angular is extremely bulky and large in size, roughly close to 550-600kb which might not be suited for most small-scale applications.
• Poor SEO – Angular struggles with SEO due to acute accessibility issues cornered with search engine crawlers/spiders. If SEO is your prime focus, React is a much better SEO friendly alternative.
• Difficult migration – Even though AngularJS(angular 1) is now obsolete, many applications are still running this legacy version. Migrating from Angular 1 to Angular(current version 9) is extremely painful and cumbersome. Angular is developing at such a rapid pace, migration among new Angular versions can also be challenging sometimes.
• Steep Learning Curve – Compared to React and especially Vue, Angular has a very steep learning curve which might present a daunting scenario for newbie developers. Angular requires a thorough knowledge of MVC to master.

Prominent websites built with Angular

Google, Allegro, Blender, Click Up, Clockify, Delta, Deutsche Bank, DoubleClick, Freelancer, Forbes, Guardian, IBM, Instapage, iStock, JetBlue, Lego, Mailerlite, Microsoft Office, Mixer, Udacity, Upwork, Vevo, Walmart, Weather, WikiWand, Xbox, Youtube.

 #3 Popular front-end JavaScript frameworks – Vuejs

The 3rd place in our best JavaScript framework of 2021 rankings in the front-end category goes to Vue.js. Vue.js is an open-source lightweight front-end JavaScript framework used to build creative user interfaces and high-performance single-page web applications with minimum effort.

Vue was first launched in 2014 by Evan You, a developer working for Google who took inspiration from Angular to deliver a simple lightweight, and efficient alternative in the form of Vue.js. Although Vue has adopted most of its features from React and Angular, it has made major improvements on those features to deliver a better, easy to use, and secure framework. The biggest example of this approach is that Vue offers a 2-way data binding as seen in Angular and ‘Virtual DOM’ as seen in React.

Likewise Vue offers high flexibility – not only can it function as an end-to-end full-fledged framework like Angular but also a view layer with state management like React. Thus, the principal key advantage of Vue is its simpler, uncomplicated, unrestrictive and progressive nature that adapts to developer’s needs. Vue has witnessed a massive explosion in its popularity over the last 2 years, dethroning Angular as the main rival to challenge the dominance of React as the best front end JavaScript framework. One of the world’s largest companies like Adobe, Apple, BMW, Louis Vuitton, Nintendo are using Vue.

Pros of using Vue

• Simplicity – The strongest ace that Vue.js has in its corner is its stupendous simplicity. Any React or Angular Developer can pick up Vue in a heartbeat without breaking a sweat. Structure of Vue is simple and enables you to code more with type less syntax. Vue uses a single file component system which means that for any given component, HTML, CSS and JavaScript all reside in a single file.
• Built in MVC – Vue has an inbuilt MVC that enables quick and easy configuration unlike React.
• Easy to learn – Vue does not require you to learn JSX or Typescript like in the case of React or Angular. Vue makes use of easy to grasp HTML templates that does not increase the complexity of code.
• Small size – Another key advantage of Vue is its surprising lightweight size given its impressive prowess. The gzipped version of Vue is barely 18-20kb in size, much lighter than its bloated bulky rivals like React or Angular.
• Documentation – Vue is blessed with arguably the best documentation among all other frameworks on this list. Any beginner with basic knowledge of JavaScript should be up and running with Vue in a couple of hours thanks to well written and thorough documentation.
• Integration – Vue can not only be used to create applications from scratch at a blazing fast face, it can also be integrated into existing web apps seamlessly without any trouble for creating new components.

Cons of using Vue

• Small community of contributors – Vue.js does not enjoy the backing of a giant like Facebook or Google like in the case of React or Angular. But Vue has indeed managed to create a community of backers. On github, Vue has 291 Contributors which is decent but still nowhere close to the kind of backing React enjoys with 1.6k contributors. Still kudos to Evan and his team for successfully creating one of the most powerful and loved frameworks the dev community has ever seen.
• Limited employment Opportunities as compared to React and Angular – Vue is undoubtedly extremely popular in China and the US but that might not be the case in the rest of the world. Traditionally the US is always the leader in new technology adoption with the rest of the world lagging behind. Popularity of Vue has not yet caught up in the rest of the world like the US. This can be verified by the fact that out of 720k currently live websites built with Vue.js, more than 450k are registered in the US alone.

Prominent websites built with Vue

9gag, Adobe, Apple Swift UI, Behance, Bilibili, BMW, Chess, Font Awesome, Gitlab, Hack the box, Laravel, Laracasts, Louis Vuitton, Namecheap, Netlify, Netguru, Nintendo, Pluralsight, Pornhub, Shien, Stack overflow, Trivago, Trustpilot, Upwork, Wizzair, Zoom.

Relate: Hire Vue.js Developers

#4 Popular front-end JavaScript frameworks – Svelte.js

The 4th place in our list of best JavaScript frameworks of 2021 in the front-end category goes to Svelte.js. Svelte.js is an open-source component-based front- end JavaScript framework written in Typescript. It was created by ex-Guardian front end developer Rich Harris. Svelte was first launched in 2016 and has ever since witnessed an absolute explosion in popularity.

Many developers consider Svelte to be a truly game-changing and revolutionary idea that fundamentally changes the way we code web applications and are tipping Svelte to dethrone React as the most popular front-end framework in the world.

Svelte, unlike React or Vue, has no virtual DOM. Instead, you build components boilerplate-free in simple HTML, CSS, and JavaScript code. Svelte Compiler then compiles this code into small framework-free vanilla JavaScript modules during build time and surgically updates the DOM when the state changes. So unlike other traditional frameworks like React or Vue, Svelte does not require high browser processing.

As a result, apps built with Svelte are lightning-fast with excellent performance. Other major advantages include zero client-side dependencies, absence of complex state management libraries, including Svelte can boast big names like Godaddy, Razorpay, 1password, New York Times as its clients.

Pros of using Svelte

• Component based Model –Svelte.js follows the same component-based model as a framework like React or Vue. New improved reactivity features in Svelte version 3 has made the task of building reusable components even faster and simpler by writing less code.
• Easy to learn – Svelte has a gentle learning curve and is arguably most suited for new developers. Reusable Components are built with simple HTML, CSS, and JavaScript code; no additional knowledge of typescript or JSX is required.
• Small Size – Svelte has one of the smallest bundle sizes among all other libraries/frameworks as it has no bulky JavaScript framework runtime overhead and is simply a compiler.
• Excellent Performance – As stated earlier, Svelte does not have a virtual DOM like React, instead relies on reactive programming to surgically update the DOM. As a result, Svelte is able to achieve the fastest rendering compared to almost any other framework and tops most of the performance benchmarks.
• SEO – Unlike some other framework that struggles with search engine crawlers, Svelte is SEO friendly.
• Supports client-side as well as server-side rendering.

Cons of using Svelte

• Limited user base – Even though Svelte has won critical acclaim and laurels in the developer community, it is yet to be adopted widely in the industry. Svelte.js does have a few big name clients under its belt but the number of websites running Svelte are barely 3-4 thousand and that too mostly in the United States of America.
• Small community and resources.
• Lack of tooling – One of the biggest complaints against Svelte has been its poor immature tooling for debugging applications.
• Lack of third party components – Unlike other framework React that has a plethora of third party component libraries like – React Bootstrap, Material UI, Semantic UI, Ant design etc, Svelte is still sorely lacking in this domain.
• Scalability issues – Some developers might feel that Svelte is difficult to scale as it doesn’t officially support Typescript.

Prominent websites built with Svelte

1Password, AB Lab, Absolute Web, Bekchy, BlueHive, Cashfree, Chess, Comigo, Entur, Farmbox, Fusion Charts, Godaddy, HealthTree, Rakuten, Razorpay, The New York times.

Popular back-end JavaScript frameworks

One of the key reasons behind JavaScript’s wild success and its ascend to the throne of the world’s most popular programming language is it’s versatility. Not only can JavaScript be used for front-end client-side development but back-end server-side development as well thanks to Node.js. There are several server-side javascript frameworks available to choose from, Express.js is the most popular choice. However, you must keep in mind important factors such as performance, scalability, flexibility, and nature of your web application before making a choice. Here are the top 4 javascript frameworks of 2021 for the backend.

#1 Back-end JavaScript frameworks – Express.js

The 1st place in our list of best JavaScript Frameworks of 2021 in the bank-end category goes to the venerable Express.js. Express.js is an open-source minimal and un-opinionated web framework for Node.js used for building APIs and web applications. It’s so popular that it is considered to be the best JavaScript framework for back-end with Node.js, especially in MEAN or MERN stacks. With almost 48k stars, it’s the most popular Node framework on Github.

Express was originally built by TJ Holowaychuk in 2010 before being acquired by IBM(StrongLoop) in 2015. It is currently maintained by Node.js Foundation. The key advantage of using Express is rapid server-side coding. Complex tasks that would take hours to code using pure Node.js can be resolved in a few minutes thanks to Express. On top of that Express offers a robust routing mechanism for handling highly dynamic URLs as compared to the basic and rudimentary one offered by Node.js.

Express also makes debugging an effortless task by easily pin-pointing bugs. Another benefit of using Express is that it provides a templating engine to dynamically render HTML pages on the server-side rather than client-side which makes web application more efficient. Express unsurprisingly has the largest share among all back end JavaScript frameworks and is used by major corporations like – Accenture, IBM, and Paypal.

Pros of using Express.js

• Community support – Express is a really mature 10 year old framework with a massive community backing. Express boasts more than 1.6k contributors on Github.
• Good Documentation – Express is blessed with well written and thorough documentation along with a huge trove of tutorials and resources.
• Fast paced development – Simplifies and accelerates developing web applications using Node.js.
• Middleware – Express is technically a series of middleware function calls. Middleware functions perform various tasks like executing code, making changes to request and response objects and ending request-response cycle. Express has 5 types of middleware – Application-level, Router level, Error-handling, Built-in and third party middlewares.
• Routing – Offers a powerful routing mechanism to define routes based on URLs and HTTP methods.
• Integration with databases – Express offers seamless connectivity with all major popular databases like MongoDB, MySQL and Redis.
• Integration with Template engines – All popular template engines like Pug, HAML, EJS, work out of the box with Express.
• Easy to learn – Express is undoubtedly the easiest backend framework for newbie developers thanks to simple syntax and structure. You only need knowledge of vanilla JavaScript and Node fundamentals as a prerequisite.

Cons of using Express.js

• Ensuring security of the web application is entirely up to the developer and quality of the code. Express by itself doesn’t offer any security solution.
• Even though this isn’t really a disadvantage in most cases especially for experienced developers, biggers might find Express difficult to master because of its un-opinionated nature. There isn’t a defined structured way of doing things to guide beginners. Although, experienced developers will consider un-opinionated nature a big merit that offers more flexibility and freedom.

Prominent Websites Built With Express

Accenture, Coursera, Exove, Fox, Godaddy, IBM, Myntra, Nike, Paypal, Pluralsight, Quizup, Ripjar, Sony Playstation, Twitter, Uber, Unsplash, Yandex.

#2 Back-end JavaScript frameworks – Next.js

The 2nd place in our list of best JavaScript frameworks of 2021 in the bank-end category goes to Next.js.

Next.js is an end-to-end server-side rendering framework based on React. Next.js was created by Dutch company Vercel(previously known as ZEIT) in 2017. Although both Next and Gatsby are based on React, there is one key difference between the two. While Gatsby is a static site generator, Next is essentially SSR- Server-side renderer.

But remember Next does offer static generators as well. Next is built with the principle of “Build once, runs everywhere” which means that not only can you make web applications with Next.js but also mobile apps, desktop apps as well as Progressive Web apps.

The major advantages of using Next.js are – automatic code-splitting, hot code reloading, automatic routing, and built-in handling of SEO to name a few. Next has the privilege of stating major tech companies like Github, Docker, and Netflix as its users.

Pros of using Next.js

• Server Side Rendering –Next.js has SSR(server-side rendering) out of the box to deliver much faster performance as it doesn’t have to wait for the client’s browser to load JavaScript to show content. SSR, also sometimes referred to as “static pre-rendering” , starts to render HTML from the server even before JavaScript code has been downloaded in the client’s browser and executed. As a result, the initial render of the application is available even when code is still loading in the background.
• SEO friendly – Traditional Client side rendered apps have a poor SEO performance. Search engine crawlers face difficulties in indexing such pages. However Next.js with its server side rendering capability delivers an excellent SEO performance. Next.js allows us to create dynamic meta tags in the head section to optimise SEO.
• Automatic code splitting – this feature in Next.js allows us to break down our application code into a series of small bundles which are loaded separately as needed without the need to lead the entire JavaScript code. This helps to deliver blazing fast optimal performance.
• Pre-fetching – this feature in Next.js allows the lightweight bundles of JavaScript code mentioned above to be lazy loaded behind the scene.
• Hot-code Reloading – Next.js automatically reloads the page when a change is detected.
• Deploy everywhere – With Next.js you can build both small scale static websites as well as enterprise scale applications. Moreover, you can not only build web applications but also mobile apps, desktop apps as well as progressive web applications too.

Cons of using Next.js

• Gatsby might be a better option than Next.js for smaller blogs where static build delivers a much more favourable and better performance than relying on Next.js Server side rendering.
• Performance benchmarks of Next.js are in most cases inferior to Gatsby and Nuxt.
• Requires back end server side to provide data.
• Next.js is built specifically to work with React only.

Prominent websites built with Next

Auth0, Binance, Coinbase, Docker, Github, Hulu, Invision, Magic Leap, Netflix, Sesame, Starbucks, Trulia, Tencent, Twitch, Uber.

#3 Back-end JavaScript frameworks – Gatsby.js

The 3rd place in our list of Top JavaScript Frameworks of 2021 in the bank-end category goes to Gatsby.js. Gatsby.js was founded by Kyle Mathews and Sam Bhagwat, and launched around May 2015. Gatsby is a modern, flexible React and GraphQl based Static Site Generator used to build high performance and SEO friendly static websites. Gatsby lets users pull data from any data source imaginable – CMS like WordPress, Drupal, Netlify, Contentful etc or APIs, databases or simple markdown. Unlike Next.js which we discussed above, Gatsby does not perform server-side rendering. Instead it generates HTML content on the client side during build time. As a result Gatsby.js delivers blazing fast performance, impeccable security and good SEO performance. Another major advantage that Gatsby offers is plugins that add key functionalities and modifications to make your life easier. These range from enhancing UI/UX, using styled components, integration with key services like Email marketing tools or CMS, SEO, image optimisation, setting up google analytics, creating sitemaps, robot txt files, caching etc. Gatsby.js is used by major brands like Airbnb, Nike, edx.org, Figma to name a few.

Pros of using Gatsby.js

• Fast Performance – Websites built with Gatsby.js are usually 2-3 times faster than normal websites built with other tech stack. Gatsby automatically compiles the most appropriate webpack config and handles optimisation, prefetching, lazy loading and fast rendering by default to maximise your website’s performance.
• SEO Friendly – Static content generated by Gatsby.js is easily readable by Search engine crawlers and offers no hindrance like other JavaScript frameworks.
• Out-of-the-box PWA – Gatsby.js converts your website into a full fledged Progressive Web App that enhances user experience to the maximum.
• Supports Multiple Data sources – Gatsby collects data not only by markdown but also various other remote data sources like WordPress, Drupal, Netlify, Contentful, Trello, Stripe etc.
• High Security – Gatsby offers implicit security as it does not require any server, database or dependencies.
• Plugins – Gatsby’s rich and extensive plugin architecture will offer you a plugin for every task that you can hope to accomplish – image optimization, setting up google analytics, creating sitemaps, robot txt files, caching etc.

Cons of using Gatsby.js

• Not suitable for large scale websites – Gatsby.js is not an ideal solution for content-heavy enterprise scale websites like e-commerce stores or media extensive websites. Build time will drastically increase as the size of content grows. This will lead to a significant drop in website performance. Gatsby is a perfect solution for small or even medium scale applications but large enterprise scale websites.
• Prerequisite knowledge – Although learning how to use Gatsby is fairly easy, a perquisite knowledge of React and a little GraphQl is necessary.
• Hosting – Hosting with Gatsby is not straight forward like using a normal website on Site ground, GoDaddy or HostGator.

Prominent websites built with Gatsby

Airbnb, Braun, edx.org, Fabric, Figma, Flamingo, Freecodecamp, Ghost, Hopper, Impossible, Nike, Paypal, React, Segment, Sendgrid, Snapkit.

#4 Back-end JavaScript frameworks – Nuxt.js

The 4th place in our list of Top JavaScript Frameworks of 2021 in the bank-end category goes to Nuxt.js. Nuxt.js is an open source progressive framework based on the Vue ecosystem used to build performant web applications especially server-side rendered apps. It can be considered as an enhancer for Vue. But keep in mind Nuxt.js is not a substitute for Vue as it cannot function alone. And neither can it be considered a full-fledged backend framework like Express. Nuxt.js is a combination of official vue libraries and components – Vue, Vue Router, vuex, vue server renderer and vue meta while also packing the prowess of webpack babel and PostCSS too. With Nuxt you can create 3 different kinds of web apps – Pre-rendered Static pages app, Single-page web application (SPA) as well as Server-side rendered web applications(SSR) or universal Apps.

Pros of using Nuxt.js

• Fast setup and development – Setting up a new project in Nuxt.js is just a matter of a few minutes thanks to the starter-template that can be created easily using the command line. Nuxt handles most of the initial setup and configuration by itself so that you can head straightaway to coding.
• Create Universal App – One of the biggest advantages that Nuxt.js offers is the ability to create Universal Apps – JavaScript code that runs on both client and server side. While traditional Single-page applications are plagued with slow loading times and poor SEO performance, Universal Apps deliver a huge loading speed boost as well as improving SEO by making content available faster for search engine bots to crawl.
• Project Structure – Nuxt by default organises your code in a logical, scalable and easy to understand structure right out-of-box. The main directories set up by default are – assets, components, layouts, pages, plugins and store.
• Code Splitting – Nuxt generates a static version of your app with the most performant webpack config. As a result, every statically generated page has its own JS file. This helps to split overall application JavaScript code into smaller files boosting speed and overall performance.
• Nuxt Community – ‘Nuxt community’ is a GitHub collection of several APIs, libraries, starter kits and modules that you would need when starting out.

Cons of using Nuxt.js

• You might face problems integrating custom libraries with Nuxt.
• Debugging issues when using Nuxt can often be quite challenging and frustrating.
• Size of community backing Nuxt is relatively small as compared to Next.js or Gatsby.js
• Documentation is not very extensive and there isn’t an abundance of good resources.

Prominent websites built with Nuxt

Aircall, Amplitude, Backmarket, Bitpay, Bootstrap Vue, Fox News, Gitlab, Icons8, Instrument, MyScript, Nespresso, Note.com, Ozon.ru, Roland Garros, System76, Todoist, Upwork, Wappalyzer.

Popular JavaScript Testing Frameworks

JavaScript is also widely used for testing websites or web applications. With more and more organizations opting for automation testing, JavaScript testing frameworks are being increasingly used for unit testing, integration testing and End-to-End testing.

#1 JavaScript Testing Frameworks – Jest

Jest ranks 1st as the best JavaScript framework for testing. It is developed by Facebook and the major focus with this JavaScript testing framework is on simplicity. It is being widely used with Selenium for JavaScript automated testing. It provides good cross browser support for automated browser testing.

Key features

• Runs isolated tests to ensure there are no performance drops
• The API is well-thought-out and maintained
• Can automatically collect code coverage information
• Easy to mock objects that are outside the test scope

Pros of using Jest

• Very simple to implement and use
• Works perfectly with Node, Angular, Typescript, Vue, React, and more
• Needs zero configuration

Cons of using Jest

• Minimal JavaScript library and tool support

Prominent websites built with Jest

Airbnb, Bla Bla Car, Circle Cl, Facebook, Instagram, Intuit, One football, Revolut, Spotify, Stack, Swat.io, The New York Times, Travel Perk, Twitter.

#2 JavaScript Testing Frameworks – Mocha

Mocha is a JavaScript testing framework which runs on node.js and is widely used for asynchronous testing. It is a feature rich JavaScript framework and tests in Mocha run serially and the reports are accurate and flexible. Mocha supports both BDD and TDD environments for JavaScript automated testing for Selenium test automation.

Key features

• Simple asynchronous support
• Asynchronous test timeout support
• Variable leak detection
• Arbitrary transpiler support

Pros of using Mocha

• Very flexible
• Supports a lot of side-tools
• Backed by a very active support community
• Offers multiple browser support

Cons of using Mocha

• Needs extensive configuration
• May offer more flexibility than needed

Prominent websites built with Mocha

Accenture, Algolia, Asana, Clay, Codefirst, Coursera, Netlify, Open Collective, Principal, Third Iron, Triple Byte, Typeform, UX Planet, Webflow, Wix, Yahoo.

Conclusion

JavaScript will continue to be the dominant force powering the development of all kinds of web applications. But choosing the best JavaScript framework for your requirement out of dozens of options available is by no means an easy task. Every framework is packed with its own unique forte and shortcomings.

Carefully pay heed to your project’s requirements and understand which set of frameworks complement your needs and can deliver that best performance at the lowest development cost and time. The learning curve, complexity, compatibility documentation, community support should also be taken into account as deciding factors apart from just performance.

Hope that this article could help you to choose the most suitable JavaScript framework for your project. Leave your comments below to let us know if your favorite JavaScript framework made it to the list or if there is any other framework that you would like to be added here. Feel free to share it with your peers and colleagues.

Or contact us to get the right advice for your project needs.

Thanks for reading!