Is React a Library or a Framework? Here‘s Why it Matters

React is one of the most widely used tools for building web user interfaces today. According to the State of JS 2020 survey, React is used by 80% of respondents, far outpacing other libraries and frameworks. But among those developers, there‘s often debate: is React a library or a framework?

As a full-stack developer who has worked extensively with React, I can say this question is more than just semantic. Understanding React‘s role as a library, and how that differs from a framework, is essential for using it effectively. Let‘s dive in.

Libraries vs Frameworks: More Than Just Terminology

To understand whether React is a library or framework, we first need to define those terms in the context of software development:

• A library is a collection of reusable code that is used to solve common problems. Libraries provide a set of functions or classes that your code calls into to perform specific tasks. The key is that your code is in control, calling into the library as needed. Examples of popular JavaScript libraries include jQuery, Lodash, and Moment.js.

• A framework, conversely, provides a structure and set of rules for building an application. With a framework, the control is inverted: the framework‘s code is in charge, and your code plugs into it. Frameworks call your code, rather than the other way around. Popular JavaScript frameworks include Angular, Vue, and Ember.

Here‘s a simple code example to illustrate the difference:

// Using a library
import { capitalize } from ‘lodash‘;
console.log(capitalize(‘hello world‘)); // ‘Hello world‘

// Using a framework
import { Component } from ‘@angular/core‘;

@Component({
  selector: ‘app-root‘,
  template: ‘‘
})
export class AppComponent {}

In the library example, our code imports and calls the capitalize function from the Lodash library. We‘re in control.

In the framework example, we‘re defining an Angular component that plugs into the Angular framework. The @Component decorator and the component lifecycle hooks are all dictated by the framework. Angular is in control.

React is a Library, Not a Framework

With those definitions in mind, let‘s look at React. React provides a set of functions for creating UI components, managing state, and more. But it does not enforce strict rules on how your application is structured or how data flows through it.

Consider this basic React component:

import React from ‘react‘;

function Greeting({ name }) {
  return ;
}

This is just a function that takes props and returns JSX. There‘s no inherent structure enforced by React. You can use this component however you see fit in your application.

This is in contrast to a framework like Angular, which has strong opinions on structuring applications around concepts like modules, components, services, and directives. An Angular application must follow Angular‘s rules.

React‘s role as a library has been affirmed by the React team. As stated in the official documentation:

React is a JavaScript library for building user interfaces.

So while React is often compared to frameworks like Angular or Vue, it‘s fundamentally a different beast. It‘s a library that provides a powerful way to build UI components, but leaves many architectural decisions up to the developer.

The Implications of React‘s Library Nature

As a full-stack developer working with React, understanding its nature as a library is crucial. It impacts everything from the way you structure your application to the tools you choose to work with. Let‘s look at some of the key implications.

Flexibility and Control

Because React is a library, you as the developer have a great deal of control over your application‘s architecture. You decide how to structure your components, how to manage state (with plain React state, Redux, MobX, etc.), how to handle routing (React Router, Reach Router, etc.), and so on.

This flexibility is powerful, as it allows you to tailor your stack to your specific needs. But it also means the onus is on you to make good decisions. With great power comes great responsibility.

The React Ecosystem

Because React itself is just a library, an entire ecosystem of supporting libraries and tools has grown up around it. These range from state management (Redux) to forms (Formik) to testing (Jest, React Testing Library) and beyond.

As a React developer, navigating and staying up-to-date with this ecosystem is a big part of the job. New libraries and best practices emerge constantly, and it‘s on you to assess whether and how to incorporate them into your work.

This is in contrast to a more full-featured framework like Angular or Ember, which provide official solutions for many common needs (forms, HTTP requests, etc.) out of the box.

Full-Stack Considerations

As a full-stack developer, React‘s library nature has ripple effects that extend beyond the front-end. Because you have flexibility in how you architect your React application, you also have more responsibility in ensuring that your front-end and back-end play nicely together.

For example, decisions around state management on the front-end (say, using Redux) will impact how you design your API endpoints on the back-end. If you‘re using a GraphQL API, you‘ll need to ensure that your React components are set up to make the right queries and mutations.

The loose coupling of libraries can also introduce challenges in a full-stack context. With a more opinionated framework, you can often rely on established conventions and patterns for how the front-end and back-end interact. With React, it‘s on you to establish and enforce those conventions across your stack.

Library Interoperability and Consistency

Working with a collection of libraries rather than a unified framework also raises questions of interoperability. Will the libraries you‘ve chosen work well together? Do they follow similar patterns and conventions?

For example, if you‘re using Redux for state management and React Router for routing, you need to ensure that they‘re set up to work harmoniously. How will your Redux actions impact your routes, and vice versa?

Over time, as your application grows and new libraries are introduced, maintaining consistency can become a challenge. Without the enforced structure of a framework, it‘s easy for different parts of your codebase to start looking very different, as different teams or developers make different choices.

As a lead developer, establishing and enforcing consistent practices across your React codebase is crucial. This might include establishing coding standards, creating reusable component libraries, and regularly reviewing code to ensure consistency.

Strategies for Success with React

Despite the challenges, React‘s popularity is a testament to the power and flexibility of the library approach. As a React developer, there are strategies you can employ to make the most of React‘s nature as a library:

1. Embrace the ecosystem, but be judicious. Stay up-to-date with new libraries and tools, but be selective in what you adopt. Evaluate each library‘s maturity, community support, and alignment with your needs before introducing it to your codebase.

2. Establish clear architectural principles. Decide early on how you‘ll handle key concerns like state management, routing, and data fetching. Document and follow these principles consistently across your application.

3. Invest in creating reusable components and utilities. The more you can encapsulate common patterns and functionalities into reusable code, the more consistent and maintainable your application will be.

4. Regularly review and refactor. As your application grows and evolves, regularly take stock of your codebase. Look for opportunities to consolidate duplicated code, update libraries, and align different parts of your application.

5. Leverage frameworks when appropriate. While React itself is a library, there are React-based frameworks like Next.js and Gatsby that provide more opinionated structures. These can be particularly useful for larger, more complex applications.

6. Foster a culture of learning and sharing. Encourage your team to stay up-to-date with the React ecosystem, to share learnings, and to continuously improve your shared practices. The React community is vibrant and ever-evolving, and staying engaged with it is key to long-term success.

Conclusion

Is React a library or a framework? It‘s a library, and that distinction matters deeply for how we use it. As a full-stack developer, understanding React‘s role as a library is essential for making the most of its flexibility and power.

Working with React means embracing a vibrant but complex ecosystem, making careful architectural decisions, and continuously navigating the balance between flexibility and consistency.

But for those who master it, React‘s library approach offers unparalleled opportunities to craft powerful, tailored web applications. By understanding and strategically leveraging React‘s nature as a library, we can build robust, maintainable applications that take full advantage of this transformative tool.