What is Preact? A Fast and Lightweight React Alternative

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Scott Cosentino
Software Developer

Preact is quickly gaining attention as a go-to framework for developers because of its lightweight design, simple API, and small size. Its fast build times and compatibility with React make it a good choice for building high-performance apps. Developers can take advantage of React’s vast library and ecosystem, making Preact a versatile and powerful tool. It’s also widely used in the industry, with companies like Lyft and Uber taking advantage of the framework’s capabilities.

In this article, we’ll explore various uses and key benefits of Preact, ranging from building MVPs to complex Progressive Web Applications (PWAs). We’ll also look at how it compares to React and help you determine if Preact is the right choice for your next project. 

What is Preact? 

Preact is a JavaScript library designed to be an efficient and lightweight alternative to React. It’s also compatible with React, so developers can scale an MVP into a full React application if needed. Preact has a small virtual DOM and, weighing only 3KB in size, it enables quick transfers from server to client and optimizes load times. Preact also provides a compatibility layer with React and works great as a drop-in replacement. This makes it easy for developers to incorporate into their current applications since the same code and libraries can be used, but with better performance. 

Best Uses and Key Benefits of Using Preact

It’s clear why Preact is so popular: it’s incredibly versatile and easy to use, making it an ideal choice for a variety of projects. Many companies have successfully taken advantage of Preact’s capabilities to build practical and useful applications for their customers. Let’s take a look at some of the top uses and advantages Preact can offer. 

The benefits of using Preact for web applications

Preact is Compatible with React: Preact’s compatibility with React makes it a great choice for building lightweight, yet feature-rich applications. Using just Preact, developers can implement the majority of traditional React features and use preact/compat to pull in extra components from React if needed. This means you can include only the components you actually need, resulting in less code.

Preact has Faster Build Times than React: A key benefit of Preact is its ability to be used without any transpilation. To compare with React, developers typically need to transpile code into JavaScript, which can slow down the development process. Preact, on the other hand, is designed to get applications up and running quickly. It speeds up build times, giving developers a quicker start and making testing their ideas easier. Its straightforward design makes it easy to use and learn, allowing developers to focus on building their applications rather than struggling with complex frameworks.

Preact has a Reduced Package Size: Preact’s smaller size can lead to impressive response times, making it an ideal choice for apps that prioritize performance. A great example of this is Uber and their m.uber web application. Using Preact instead of React was necessary for Uber’s application to be successful, as it needed to be compatible with all modern web browsers and low-end devices. Preact’s speed and ease of use enabled Uber to maintain the same features of their React application while taking advantage of Preact’s small size and optimizing the application for low-end devices.

Preact is Well-Suited for Building MVPs: Preact is ideal for projects where fast development and response times are required. Its lightweight design and fast build times make it a good choice for building MVPs because developers can quickly develop the basic functionality of an application and gather feedback about the product. Also, because Preact is compatible with React, developers can easily scale MVPs into full-blown products, incorporating any necessary functionality from React or Preact.

Preact is Well-Suited for Building Progressive Web Applications: Uber’s use of Preact highlights another key use case: building Progressive Web Applications. PWAs are websites that have been designed to look and act like mobile apps, and are an amazing option if:

  • You don’t have a native app, 
  • You’d like to use one codebase to support multiple devices, or 
  • You need to support devices that can’t use your native app.

Preact’s lightweight design makes it an ideal choice for building complex PWAs – it helps reduce your application’s load time and can easily perform well on a variety of devices. Its high-performing virtual DOM also ensures a smooth and responsive user experience. 

Is Preact Suitable for Large Apps?

Preact is also a popular choice for building larger applications because of its user-friendly documentation, CLI, and speedy and reliable UIs. These features make it well suited for applications where loading time is critical and for projects that require modern JavaScript syntax.

Benefits of using Preact for large Applications

There isn’t any reason why you shouldn’t use Preact for building larger applications. However, there are a few things to consider before doing so.

Limitations or disadvantages of using Preact for Large Apps

Since Preact is compatible with React, by definition, it needs to mimic what React does. This means there’s a risk that newer React features or dependencies might not be supported by Preact immediately or at all. Also, you may need to maintain additional libraries like preact-compat for compatibility with React, which can be a burden. Finally, Preact lacks synthetic event handling, which can potentially cause performance and maintenance issues. 

These are some minor considerations to be aware of when deciding to start projects using Preact. Many companies trust Preact for their large-scale projects, so it’s likely that Preact will be sufficient for most applications you want to develop. If the initial load performance is a critical aspect of your application, then choosing Preact over React is the better choice.

Preact vs React: Key Features and Main Differences

Deciding between React or Preact really depends on your project’s specific needs and requirements. Although they have many similar features, there are some key differences.

Preact vs React key features and differences

To determine which option is the better fit, consider whether Preact’s functionality is sufficient or if you require additional features offered by React. Other factors such as the complexity, size, and performance of your project can also be taken into account when weighing your options.

  • Complexity: If your project requires a more feature-rich and flexible API, React may be the better choice. Preact has a simpler API and may not offer all the advanced features of React.  
  • Size: Preact has a smaller bundle size than React, which can be beneficial for optimizing application load times and reducing bandwidth usage. If size is a key consideration for your project, Preact may be a better choice.  
  • Performance: Preact has a faster and more efficient virtual DOM implementation than React, making it well-suited for building high-performance applications. If performance is a key concern for your project, Preact may be a better choice. 
Choosing Preact vs React comparison

Additionally, aspects like compatibility, the framework’s ecosystem, and developer preferences may help your decision: 

  • Compatibility: If you’re already using React in your project and are just looking to enhance performance, Preact might be the right choice for you as it’s fully compatible with React. However, if you’re starting a new project from the beginning, it might be a good idea to check out both frameworks and decide which one fits your needs best.
  • Ecosystem: React’s vast ecosystem and lively community offer plenty of resources and support – making it a great choice. That said, even though Preact has a smaller ecosystem, developers can still benefit from React libraries and resources.
  • Developer preferences: Ultimately, the decision of whether to go with React or Preact could be based on your preference. It may be beneficial to think about which framework your team is most accustomed to and which one they feel the most confident utilizing.

It’s important to carefully consider the trade-offs of each framework and choose the one that is best suited to meet the needs of your project. Preact’s compatibility with React makes it a good choice for starting new projects, as it allows you to leverage the simplicity and performance of Preact while still having the option to use React components if needed. With that being said, there are a few advanced React features not available in Preact. These features include:

  • PropType validation isn’t included because it’s not commonly used. However, developers can add it using the preact-compat package if needed. 
  • React.children isn’t typically needed in Preact because props.children is always an Array. 
  • Synthetic events are excluded to reduce extra overhead in the package.
Advanced React features not available in Preact

React is a more mature framework compared to Preact. It has more features and a wider range of developer tools and resources, so if your project requires any advanced features or capabilities than what Preact offers, you may want to consider using React instead.

Is Preact the Right Fit For Your Software Project?

Preact is quickly gaining popularity and recognition as a powerful alternative to React. Its small size, fast build cycles, and similarities to React have made it a useful tool for a variety of projects. Preact is also simple to learn and easy to implement, especially for React developers. Its compatibility layer allows you to use a variety of packages from the React ecosystem. Overall, Preact is a versatile framework that can be a great choice for many different projects.


Key Takeaways

What is Preact?

Preact is a JavaScript library designed to be a more efficient and compact option than React. It’s also compatible with React, allowing developers to upgrade from an MVP to a full React application if required. Preact’s small size (3KB) enables quick transfers from server to client and optimizes load times. It also provides a compatibility layer with React, making it easy for developers to incorporate into their current applications to improve performance.

Is Preact better than React?

The best choice between Preact and React depends on the requirements of your project. Preact is a great option for projects that prioritize speed and optimization, as it features a smaller bundle size and a faster virtual DOM. On the other hand, React is a better fit for more intricate projects, as its API is more feature-rich and flexible. When choosing between the two, it's important to consider the specific needs of your project.

What is different between React and Preact?

React and Preact are JavaScript libraries used for creating user interfaces. Both use a virtual DOM, but there are some key distinctions between them. For instance, React offers a more feature-rich and flexible API, whereas Preact has a smaller bundle size and faster virtual DOM implementation, making it better suited for certain types of projects.

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