What is React.js Used For: Top 10 Examples

React.js is a frontend JavaScript library used primarily for building single-page and multi-page interfaces. It is one of the most widely adopted web technologies in the world, and the range of companies using it – from social media platforms to financial services to publishers – reflects its versatility.

Even though programming technologies come and go, a few hold their positions through successive waves of new frameworks. React.js is one of them. According to the 2025 Stack Overflow Developer Survey (49,000+ respondents), React is used by 44.7% of developers – making it the second most-used web framework globally, behind Node.js at 48.7%.

The library's popularity among developers translates directly into business adoption. Following the judgment of their engineering teams, numerous companies chose React.js as their primary frontend technology – for reasons that go beyond developer experience alone.

React.js is rarely described as easy to learn. It is flexible, extendable, and powerful, but not immediately accessible for beginners. 

As a library rather than a framework, it imposes few opinionated rules – developers can shape it to their needs, but fluency requires real experience. That said, the demand for React developers has grown steadily for over a decade, and the extensive ecosystem of tools, libraries, and community resources makes building that fluency worthwhile.

Read more: What is React.js and when to choose it for app development

The Business Advantages of React.js

Productivity

In modern applications, the frontend layer needs to be easy to update and extend. When every UI component is unique, that becomes difficult. React addresses this by enabling developers to build reusable UI components. 

Managing the UI layer becomes straightforward, and components can be reused across new applications with the same functionality – reducing development effort and shortening time to market.

SEO- and UX-Friendliness

React.js favors building lightweight, performant applications – a factor that matters both for user experience and SEO. 

Application performance became a key ranking signal when Google made Core Web Vitals a significant part of its algorithm, and React's fast rendering helps applications meet those performance thresholds.

Strong Support

React is used by Facebook, Netflix, Yahoo, Codecademy, Dropbox, Airbnb, Asana, Microsoft, Slack, and many others. 

Despite the learning curve introduced by JSX – which mixes visual elements with logic – the large, active community around React flattens that curve significantly. The depth of available documentation, tooling, and community support is one of the practical reasons companies continue to choose it.

Top 10 Examples of React.js Applications

1. Facebook and React.js

Facebook could not be missing from a list of React users – it was React's origin and continues to support its development. 

React is not the only technology in Facebook's stack, but it serves as a significant part of the script layer in the Facebook web application. React is maintained by Meta and a community of developers, with the core library hosted at react.dev.

2. Instagram and React.js

As part of Meta's product portfolio, Instagram also benefits from React across features including geolocations, Google Maps API integrations, and search. 

In 2016, Instagram started switching to React Native to accelerate shipping new features on both iOS and Android versions. Meta's engineering blog documents ongoing React work across both platforms at engineering.fb.com.

3. Dropbox and React.js

Dropbox chose React for its ability to deliver an excellent user experience through smaller file sizes and faster reloading speeds. React also provides the foundation for Dropbox's online backup solutions and cloud-based storage interface. 

Dropbox's engineering blog at dropbox.tech documents their frontend work, and current job postings confirm React and TypeScript as the primary frontend technologies.

4. Discord and React.js

Discord, initially built for gaming communities, uses React.js for its web application and React Native for mobile. 

The platform's December 2025 patch notes confirm they updated React Native on their mobile applications from 0.78 to 0.81.4 – active, current usage. 

Discord's engineering posts on their React Native work are documented at discord.com/blog.

5. Netflix and React.js

Netflix chose React because its component-based architecture enables reusable UI elements across a vast content library, improving code efficiency and maintainability. 

The virtual DOM allows quick rendering of dynamic content changes – essential for a platform that constantly updates recommendations, metadata, and streaming controls. 

Netflix TechBlog has a dedicated React tag with ongoing posts about their React-based micro frontend architecture.

6. Pinterest and React.js

Pinterest migrated to React in 2015 and has used it as their primary frontend framework since. 

A 2025 Pinterest Engineering blog post on their internal developer platform PinConsole documents active use of React.lazy, Suspense, and server-side rendering. 

Pinterest Engineering's React work is published at medium.com/pinterest-engineering.

7. The New York Times and React.js

The New York Times uses React.js to create a more immersive user experience. 

As one of the few publishers able to monetize paywalled content successfully, the Times understood that UX directly drives reader loyalty. In 2024, a Times engineering team implemented React 18 for their flagship core news site – confirming ongoing, current React adoption. 

The Times also built a standalone React-based application called the Red Carpet Project, describing React as a "lightweight, powerful, battle-tested library for building user interfaces with JavaScript." The Times' engineering work is documented at open.nytimes.com.

8. Airbnb and React.js

Airbnb adopted React as its canonical frontend view framework in 2015 and continues to invest in it at scale. 

In July 2024, their engineering team published a post on how Airbnb smoothly upgrades React, describing the upgrade of all web surfaces from React 16 to React 18. 

Airbnb's contribution to the React ecosystem goes beyond adoption: their React/JSX Style Guide – open-sourced and widely adopted – provides comprehensive best practices for React code quality, covering component structure, props usage, and JSX conventions.

9. Reddit and React.js

Reddit uses React for its frontend user interface, supporting the dynamic rendering of comment threads, voting systems, and content feeds at very high traffic volumes. 

React's efficient rendering has been key in maintaining performance despite constant, high-volume user engagement. Reddit's engineering blog is at reddit.engineering.

10. PayPal and React.js

PayPal has developed and maintains official React components for integrating PayPal payments into React applications.

The react-paypal-js library – actively maintained, with the README last updated in March 2026 – provides hooks-based React components for the PayPal JS SDK v6.

PayPal's official JS SDK documentation includes interactive React component demos. This makes React a core part of PayPal's developer platform strategy.

Is There Any Drawback to Using React?

React can be used for applications ranging from large to small across virtually any sector. 

Health and fitness apps use it for building flexible dashboards wrapping workout plans and health tracking features. Cybersecurity tools use it because it receives regular updates and security vulnerability patches. Finance relies on React's data visualization capacity. Education platforms appreciate it for the interactive learning experiences it enables.

That said, React has real drawbacks worth acknowledging.

JSX mixing of concerns. React requires developers to mix HTML-like markup directly with JavaScript logic through JSX. This can be confusing for developers coming from a strict separation-of-concerns background, and the "right" way to structure components is not always obvious without experience.

State management complexity at scale. React itself manages component-level state, but large applications typically need additional state management libraries (Redux, Zustand, Jotai, or the React Context API). Choosing and implementing the right approach adds architectural complexity, and prop drilling – passing data through many component layers – is a common pain point in codebases that grow without a clear state management strategy.

Ecosystem churn. React's flexibility means there is rarely one standard way to solve a problem. The ecosystem of supporting libraries (routing, form handling, data fetching, styling) evolves quickly, and patterns that were standard a few years ago may now be considered outdated. Keeping a React codebase current requires ongoing investment from the engineering team.

These trade-offs don't diminish React's value – they frame the conditions under which it works best: experienced developers, projects where UI complexity is a genuine challenge, and teams willing to invest in architectural decisions upfront.

Monterail's React.js Experience

React has been part of Monterail's technology stack across a range of projects. 

The Seat Unique premium ticketing platform was built on Ruby on Rails with a React frontend, and the team later migrated to Next.js as the product scaled. Over an 8-year partnership, Seat Unique grew 7,900%+ in revenue, raised £14.5M in 2025, and now handles over 1 million visitors per month and 6,000+ transactions per month.

The lesson from that partnership is consistent with what the broader ecosystem shows: React is not a silver bullet, but it is well-suited to applications where the UI is complex, the user base is large, and the development team needs to ship and iterate quickly without sacrificing quality.

If you're evaluating React.js for a new project or looking for an experienced team to build or maintain a React application, Monterail's web development team can help.

Why React.js Remains a Strong Choice

React.js is the library teams consistently reach for when UX quality, developer experience, and application performance are the primary success factors. Performance, speed, the ability to add features incrementally, flexibility, scalability, and a deep developer community are the reasons companies from startup scale to global platforms continue to choose it.

The 2025 Stack Overflow Developer Survey confirms that its position remains strong: 44.7% of developers use React, a figure that has grown consistently since the library's introduction. For organizations that need a battle-tested frontend technology with a large talent pool and a mature ecosystem, React.js remains one of the most defensible choices available.