JavaScript - - By Pavels Jelisejevs

React vs Angular: An In-depth Comparison

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Should I choose Angular or React? Today’s bipolar landscape of JavaScript frameworks has left many developers struggling to pick a side in this debate. Whether you’re a newcomer trying to figure out where to start, a freelancer picking a framework for your next project, or an enterprise-grade architect planning a strategic vision for your company, you’re likely to benefit from having an educated view on this topic.

To save you some time, let me tell you something up front: this article won’t give a clear answer on which framework is better. But neither will hundreds of other articles with similar titles. I can’t tell you that, because the answer depends on a wide range of factors which make a particular technology more or less suitable for your environment and use case.

Since we can’t answer the question directly, we’ll attempt something else. We’ll compare Angular (2+, not the old AngularJS) and React, to demonstrate how you can approach the problem of comparing any two frameworks in a structured manner on your own and tailor it to your environment. You know, the old “teach a man to fish” approach. That way, when both are replaced by a BetterFramework.js in a year’s time, you’ll be able to re-create the same train of thought once more.

Two knights jousting, with React and Angular logos on their shields

Where to Start?

Before you pick any tool, you need to answer two simple questions: “Is this a good tool per se?” and “Will it work well for my use case?” Neither of them mean anything on their own, so you always need to keep both of them in mind. All right, the questions might not be that simple, so we’ll try to break them down into smaller ones.

Questions on the tool itself:

  • How mature is it and who’s behind it?
  • What kind of features does it have?
  • What architecture, development paradigms, and patterns does it employ?
  • What is the ecosystem around it?

Questions for self-reflection:

  • Will I and my colleagues be able to learn this tool with ease?
  • Does is fit well with my project?
  • What is the developer experience like?

Using this set of questions you can start your assessment of any tool and we’ll base our comparison of React and Angular on them as well.

There’s another thing we need to take into account. Strictly speaking, it’s not exactly fair to compare Angular to React, since Angular is a full-blown, feature-rich framework, while React just a UI component library. To even the odds, we’ll talk about React in conjunction with some of the libraries often used with it.

Maturity

An important part of being a skilled developer is being able to keep the balance between established, time-proven approaches and evaluating new bleeding-edge tech. As a general rule, you should be careful when adopting tools that haven’t yet matured due to certain risks:

  • The tool may be buggy and unstable.
  • It might be unexpectedly abandoned by the vendor.
  • There might not be a large knowledge base or community available in case you need help.

Both React and Angular come from good families, so it seems that we can be confident in this regard.

React

React is developed and maintained by Facebook and used in their own products, including Instagram and WhatsApp. It has been around for roughly three and a half years now, so it’s not exactly new. It’s also one of the most popular projects on GitHub, with about 74,000 stars at the time of writing. Sounds good to me.

Angular

Angular (version 2 and above) has been around less then React, but if you count in the history of its predecessor, AngularJS, the picture evens out. It’s maintained by Google and used in AdWords and Google Fiber. Since AdWords is one of the key projects in Google, it is clear they have made a big bet on it and is unlikely to disappear anytime soon.

Features

Like I mentioned earlier, Angular has more features out of the box than React. This can be both a good and a bad thing, depending on how you look at it.

Both frameworks share some key features in common: components, data binding, and platform-agnostic rendering.

Angular

Angular provides a lot of the features required for a modern web application out of the box. Some of the standard features are:

  • Dependency injection
  • Templates, based on an extended version of HTML
  • Routing, provided by @angular/router
  • Ajax requests by @angular/http
  • @angular/forms for building forms
  • Component CSS encapsulation
  • XSS protection
  • Utilities for unit-testing components.

Having all of these features available out of the box is highly convenient when you don’t want to spend time picking the libraries yourself. However, it also means that you’re stuck with some of them, even if you don’t need them. And replacing them will usually require additional effort. For instance, we believe that for small projects having a DI system creates more overhead than benefit, considering it can be effectively replaced by imports.

React

With React, you’re starting off with a more minimalistic approach. If we’re looking at just React, here’s what we have:

  • No dependency injection
  • Instead of classic templates it has JSX, an XML-like language built on top of JavaScript
  • XSS protection
  • Utilities for unit-testing components.

Not much. And this can be a good thing. It means that you have the freedom to choose whatever additional libraries to add based on your needs. The bad thing is that you actually have to make those choices yourself. Some of the popular libraries that are often used together with React are:

We’ve found the freedom of choosing your own libraries liberating. This gives us the ability to tailor our stack to particular requirements of each project, and we didn’t find the cost of learning new libraries that high.

Languages, Paradigms, and Patterns

Taking a step back from the features of each framework, let’s see what kind higher-level concepts are popular with both frameworks.

React

There are several important things that come to mind when thinking about React: JSX, Flow, and Redux.

JSX

JSX is a controversial topic for many developers: some enjoy it, and others think that it’s a huge step back. Instead of following a classical approach of separating markup and logic, React decided to combine them within components using an XML-like language that allows you to write markup directly in your JavaScript code.

While the merits of mixing markup with JavaScript might be debatable, it has an indisputable benefit: static analysis. If you make an error in your JSX markup, the compiler will emit an error instead of continuing in silence. This helps by instantly catching typos and other silly errors.

Flow

Flow is a type-checking tool for JavaScript also developed by Facebook. It can parse code and check for common type errors such as implicit casting or null dereferencing.

Unlike TypeScript, which has a similar purpose, it does not require you to migrate to a new language and annotate your code for type checking to work. In Flow, type annotations are optional and can be used to provide additional hints to the analyzer. This makes Flow a good option if you would like to use static code analysis, but would like to avoid having to rewrite your existing code.

Redux

Redux is a library that helps manage state changes in a clear manner. It was inspired by Flux, but with some simplifications. The key idea of Redux is that the whole state of the application is represented by a single object, which is mutated by functions called reducers. Reducers themselves are pure functions and are implemented separately from the components. This enables better separation of concerns and testability.

If you’re working on a simple project, then introducing Redux might be an over complication, but for medium- and large-scale projects, it’s a solid choice. The library has become so popular that there are projects implementing it in Angular as well.

All three features can greatly improve your developer experience: JSX and Flow allow you to quickly spot places with potential errors, and Redux will help achieve a clear structure for your project.

Angular

Angular has a few interesting things up its sleeve as well, namely TypeScript and RxJS.

TypeScript

TypeScript is a new language built on top of JavaScript and developed by Microsoft. It’s a superset of JavaScript ES2015 and includes features from newer versions of the language. You can use it instead of Babel to write state of the art JavaScript. It also features an extremely powerful typing system that can statically analyze your code by using a combination of annotations and type inference.

There’s also a more subtle benefit. TypeScript has been heavily influenced by Java and .NET, so if your developers have a background in one of these languages, they are likely to find TypeScript easier to learn than plain JavaScript (notice how we switched from the tool to your personal environment). Although Angular has been the first major framework to actively adopt TypeScript, it’s also possible to use it together with React.

RxJS

RxJS is a reactive programming library that allows for more flexible handling of asynchronous operations and events. It’s a combination of the Observer and Iterator patterns blended together with functional programming. RxJS allows you to treat anything as a continuous stream of values and perform various operations on it such as mapping, filtering, splitting or merging.

The library has been adopted by Angular in their HTTP module as well for some internal use. When you perform an HTTP request, it returns an Observable instead of the usual Promise. Although this library is extremely powerful, it’s also quite complex. To master it, you’ll need to know your way around different types of Observables, Subjects, as well as around a hundred methods and operators. Yikes, that seems to be a bit excessive just to make HTTP requests!

RxJS is useful in cases when you work a lot with continuous data streams such as web sockets, however, it seems overly complex for anything else. Anyway, when working with Angular you’ll need to learn it at least on a basic level.

We’ve found TypeScript to be a great tool for improving the maintainability of our projects, especially those with a large code base or complex domain/business logic. Code written in TypeScript is more descriptive and easier to follow. Since TypeScript has been adopted by Angular, we hope to see even more projects using it. RxJS, on the other hand, seems only to be beneficial in certain cases and should be adopted with care. Otherwise, it can bring unwanted complexity to your project.

Ecosystem

The great thing about open source frameworks is the number of tools created around them. Sometimes, these tools are even more helpful than the framework itself. Let’s have a look at some of the most popular tools and libraries associated with each framework.

Angular

Angular CLI

A popular trend with modern frameworks is having a CLI tool that helps you bootstrap your project without having to configure the build yourself. Angular has Angular CLI for that. It allows you to generate and run a project with just a couple of commands. All of the scripts responsible for building the application, starting a development server and running tests are hidden away from you in node_modules. You can also use it to generate new code during development. This makes setting up new projects a breeze.

Ionic 2

Ionic 2 is a new version of the popular framework for developing hybrid mobile applications. It provides a Cordova container that is nicely integrated with Angular 2, and a pretty material component library. Using it, you can easily set up and build a mobile application. If you prefer a hybrid app over a native one, this is a good choice.

Material design components

If you’re a fan of material design, you’ll be happy to hear that there’s a Material component library available for Angular. Currently, it’s still at an early stage and slightly raw but it has received lots of contributions recently, so we might hope for things to improve soon.

Angular universal

Angular universal is a seed project that can be used for creating projects with support for server-side rendering.

@ngrx/store

@ngrx/store is a state management library for Angular inspired by Redux, being based on state mutated by pure reducers. Its integration with RxJS allows you to utilize the push change detection strategy for better performance.

There are plenty of other libraries and tools available in the Awesome Angular list.

React

Create React App

Create React App is a CLI utility for React to quickly set up new projects. Similar to Angular CLI it allows you to generate a new project, start a development server and create a bundle. It uses Jest, a relatively new test runner from Facebook, for unit testing, which has some nice features of its own. It also supports flexible application profiling using environment variables, backend proxies for local development, Flow, and other features. Check out this brief introduction to Create React App for more information.

React Native

React Native is a platform developed by Facebook for creating native mobile applications using React. Unlike Ionic, which produces a hybrid application, React Native produces a truly native UI. It provides a set of standard React components which are bound to their native counterparts. It also allows you to create your own components and bind them to native code written in Objective-C, Java or Swift.

Material UI

There’s a material design component library available for React as well. Compared to Angular’s version, this one is more mature and has a wider range of components available.

Next.js

Next.js is a framework for the server-side rendering of React applications. It provides a flexible way to completely or partially render your application on the server, return the result to the client and continue in the browser. It tries to make the complex task of creating universal applications as simple as possible so the set up is designed to be as simple as possible with a minimal amount of new primitives and requirements for the structure of your project.

MobX

MobX is an alternative library for managing the state of an application. Instead of keeping the state in a single immutable store, like Redux does, it encourages you to store only the minimal required state and derive the rest from it. It provides a set of decorators to define observables and observers and introduce reactive logic to your state.

Storybook

Storybook is a component development environment for React. It allows you to quickly set up a separate application to showcase your components. On top of that, it provides numerous add-ons to document, develop, test and design your components. We’ve found it to be extremely useful to be able to develop components independently from the rest of the application. You can learn more about Storybook from a previous article.

There are plenty of other libraries and tools available in the Awesome React list.

Adoption, Learning Curve and Development Experience

An important criterion for choosing a new technology is how easy it is to learn. Of course, the answer depends on a wide range of factors such as your previous experience and a general familiarity with the related concepts and patterns. However, we can still try to assess the number of new things you’ll need to learn to get started with a given framework. Now, if we assume that you already know ES6+, build tools and all of that, let’s see what else you’ll need to understand.

React

With React, the first thing you’ll encounter is JSX. It does seem awkward to write for some developers. However, it doesn’t add that much complexity — just expressions, which are actually JavaScript, and a special HTML-like syntax. You’ll also need to learn how to write components, use props for configuration and manage internal state. You don’t need to learn any new logical structures or loops since all of this is plain JavaScript.

The official tutorial is an excellent place to start learning React. Once you’re done with that, get familiar with the router. The react router v4 might be slightly complex and unconventional, but nothing to worry about. Using Redux will require a paradigm shift to learn how to accomplish already familiar tasks in a manner suggested by the library. The free Getting Started with Redux video course can quickly introduce you to the core concepts. Depending on the size and the complexity of your project you’ll need to find and learn some additional libraries and this might be the tricky part, but after that everything should be smooth sailing.

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We were genuinely surprised at how easy it was to get started using React. Even people with a backend development background and limited experience in frontend development were able to catch up quickly. The error messages you might encounter along the way are usually clear and provide explanations on how to resolve the underlying problem. The hardest part may be finding the right libraries for all of the required capabilities, but structuring and developing an application is remarkably simple.

Angular

Learning Angular will introduce you to more new concepts than React. First of all, you’ll need to get comfortable with TypeScript. For developers with experience in statically typed languages such as Java or .NET this might be easier to understand than JavaScript, but for pure JavaScript developers, this might require some effort.

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The framework itself is rich in topics to learn, starting from basic ones such as modules, dependency injection, decorators, components, services, pipes, templates, and directives, to more advanced topics such as change detection, zones, AoT compilation, and Rx.js. These are all covered in the documentation. Rx.js is a heavy topic on its own and is described in much detail on the official website. While relatively easy to use on a basic level it gets more complicated when moving on to advanced topics.

All in all, we noticed that the entry barrier for Angular is higher than for React. The sheer number of new concepts is confusing to newcomers. And even after you’ve started, the experience might be a bit rough since you need to keep in mind things like Rx.js subscription management, change detection performance and bananas in a box (yes, this is an actual advice from the documentation). We often encountered error messages that are too cryptic to understand, so we had to google them and pray for an exact match.

It might seem that we favor React here, and we definitely do. We’ve had experience onboarding new developers to both Angular and React projects of comparable size and complexity and somehow with React it always went smoother. But, like I said earlier, this depends on a broad range of factors and might work differently for you.

Putting it Into Context

You might have already noted that each framework has its own set of capabilities, both with their good and bad sides. But this analysis has been done outside of any particular context and thus doesn’t provide an answer on which framework should you choose. To decide on that, you’ll need to review it from a perspective of your project. This is something you’ll need to do on your own.

To get started, try answering these questions about your project and when you do, match the answers against what you’ve learned about the two frameworks. This list might not be complete, but should be enough to get you started:

  1. How big is the project?
  2. How long is it going to be maintained for?
  3. Is all of the functionality clearly defined in advance or are you expected to be flexible?
  4. If all of the features are already defined, what capabilities do you need?
  5. Are the domain model and business logic complex?
  6. What platforms are you targeting? Web, mobile, desktop?
  7. Do you need server-side rendering? Is SEO important?
  8. Will you be handling a lot of real-time event streams?
  9. How big is your team?
  10. How experienced are your developers and what is their background?
  11. Are there any ready-made component libraries that you would like to use?

If you’re starting a big project and you would like to minimize the risk of making a bad choice, consider creating a proof-of-concept product first. Pick some of the key features of the projects and try to implement them in a simplistic manner using one of the frameworks. PoCs usually don’t take a lot if time to build, but they’ll give you some valuable personal experience on working with the framework and allow you to validate the key technical requirements. If you’re satisfied with the results, you can continue with full-blown development. If not, failing fast will save you lot of headaches in the long run.

One Framework to Rule Them All?

Once you’ve picked a framework for one project, you’ll get tempted to use the exact same tech stack for your upcoming projects. Don’t. Even though it’s a good idea to keep your tech stack consistent, don’t blindly use the same approach every time. Before starting each project, take a moment to answer the same questions once more. Maybe for the next project, the answers will be different or the landscape will change. Also, if you have the luxury of doing a small project with a non-familiar tech stack, go for it. Such experiments will provide you with invaluable experience. Keep your mind open and learn from your mistakes. At some point, a certain technology will just feel natural and right.

This article was peer reviewed by Jurgen Van de Moere and Joan Yin. Thanks to all of SitePoint’s peer reviewers for making SitePoint content the best it can be!