— September 4, 2022
Though both of these frameworks offer extensive support for React web apps and are, in many ways, quite similar, they each have their own unique attributes that set them apart from each other and from the rest of the React ecosystem.
In today’s web development landscape, there are numerous frameworks a developer can choose to work with. Specifically for the React ecosystem, the amount of available frameworks and platforms can seem overwhelming since each has its own advantages and disadvantages. Because having a quality tech stack is of utmost importance to your developer experience and final product, it is equally important to do in-depth research into which of these many frameworks are best for your team.
In this article, we’ll investigate two popular frameworks for creating React apps: Astro and Next.js. Next.js is an established part of the React ecosystem and is used by anyone from Fortune 500 companies to solo developers. On the other hand, Astro is a relative newcomer to the frontend development landscape.
Both of these frameworks offer extensive support for React web apps and in many ways are quite similar. However, the idiosyncrasies of these two frameworks are what really sets them apart from each other and from the rest of the React ecosystem. By the end of this article, you will have a good understanding of the core differences between Next.js and Astro and be able to come to an informed decision on which framework is right for you.
First, we’ll go over the unique, defining features of these frameworks; then, we’ll review their comparable aspects; finally, we’ll discuss which framework is best for which use cases, as well as some concluding thoughts.
Before we proceed into the specifics of these frameworks, an important distinction must be made: Next.js and Astro are fundamentally different softwares.
At their most basic levels, Next.js is a full-stack framework specifically built for React, whereas Astro is a static site generator that offers support for React. Furthermore, Next.js offers both client- and server-side functionality; Astro focuses solely on the client side.
Because of this, it is nearly impossible to objectively compare these two platforms’ features since they each have different core functionalities and priorities. It is crucial to consider which are the most relevant to the technical needs of your product.
Astro’s main differentiator is its templating language. The Astro templating language was made to ensure as little of a learning curve from HTML or JSX as possible. With the templating language, you can build reusable components, layouts, etc.
You may be wondering how that is any different than a React component. While React components rely on JavaScript and the virtual DOM to load your components into the browser, Astro components require no client-side runtime. They are compiled into HTML during the build phase and are automatically loaded onto your site, enabling extra-fast performance. Pretty neat, right?
The downside to this, however, is that these are completely static components, meaning you can’t use any dynamic logic. Though you can use dynamic JSX expressions, these will simply be compiled into static values during the build phase. This is different from a reactive library like React, where you can use dynamic logic that will change the components on the client side.
Another defining feature of Astro is how it is truly library- and framework-agnostic, which means you can use whichever you choose — React, Vue, Svelte, whatever your preference. You can also mix multiple libraries in one project, enabling the usage of micro-frontends.
Astro’s focus on the client side allows it to prioritize client-side optimization and performance. This is best demonstrated in its unique partial hydration feature.
What is partial hydration? Consider that most of any app or website is non-interactive or doesn’t absolutely require client-side JavaScript for interactivity. Astro will compile these components into plain HTML that is served directly to the user.
For the parts that do require client-side JavaScript, these components are saved for individual hydration once the plain HTML has already rendered. Since you are only loading JavaScript for the components that absolutely require it, this drastically reduces your site’s bundle size, which makes it more performant.
Unlike Astro, Next.js was developed specifically with React in mind. Though you can use other React-based libraries like Preact or build pages from Markdown, Next.js is ultimately limited to React applications.
If you are interested in gaining the same advantages of Next.js with other libraries, consider using Nuxt.js for Vue and SvelteKit for Svelte, among many other offerings.
Because Next.js is solely focused on React applications, it provides a rich set of inbuilt features that can enhance your app.
Next.js offers many React components for use with the framework. For example, Next.js offers native image optimization with the next/image component and script loading strategies with the next/script component. Additionally, Next.js supports AMP functionality.
It should also be noted that with help from a next/link component, Next.js can pre-fetch and pre-load the next pages a user might visit. If you’ve ever gone to a website where the browser doesn’t appear to be loading every time you visit a new page even though the URL changes, this is essentially what’s happening behind the scenes. This feature, albeit not unique to Next.js, is one of its most notable offerings.
Though Next.js does not offer rich client-side performance and built-in optimization techniques like Astro, it compensates in its support of server-side rendering and API routes.
Server-side rendering allows your React app to be much more efficient on the client side by offloading any data fetching to the server. For example, consider an ecommerce store. When a user goes to a product page, instead of making the client fetch the data for the product on demand (which could make your app appear slow and inefficient), Next.js allows you to fetch the data for this product on the server and send a pre-built page with all of the necessary data filled in to the client.
API routes are a unique feature offered by Next.js that further increase the full-stack capabilities of the framework. As its name implies, API routes allow developers to add API endpoints to their Next.js app.
Both Astro and Next.js offer integrations and plugins to extend their respective capabilities.
Astro offers an entire page dedicated solely to integrations, which consists of anything from support for libraries like React and Vue to accessibility plugins. Some of these integrations are from the official Astro team, while others are from the community.
Next.js offers customizability via the next.config.js file, through which you can include Next.js plugins. Though there isn’t a dedicated site for all available plugins, a quick Google search will often find you exactly what you need.
Currently, Next.js far exceeds Astro offerings in terms of integrations and extensibility. However, although Astro may offer less in terms of pre-built integrations at this time, as the framework grows in popularity one can only expect the available integrations to grow as well.
Though both Astro and Next.js offer starter projects, they do it in quite dissimilar ways.
Next.js offers many examples that serve different use cases. Astro offers https://astro.new, which has different templates for different frameworks and features. Additionally, Astro offers https://astro.build/themes/, which has different themes, much like you may have seen from Gatsby or other Jamstack frameworks.
My personal preference here is Next.js. Since Next.js only supports one framework, their examples tend to be more focused and concise with specific technologies for you to grow your site with. On the other hand, Astro’s starter projects tend to be pre-built and, as such, much less customizable.
At its core, Astro is a static site generator, but Next.js also offers SSG capabilities. In fact, Next.js considers SSG to be their preferred method of pre-rendering.
Both Astro and Next.js allow for server-side data fetching to be incorporated into React components. For Astro, you must first fetch the data in an Astro component and then pass that data to the React component through a prop. For Next.js, you must use the getStaticProps in a specific page to fetch data.
The method Next.js uses is perhaps more streamlined for React apps than Astro, but ultimately this boils down to personal preference, of which I have none for this feature.
Astro and Next.js offer unique methods of optimization and performance management.
As previously discussed, Astro offers partial hydration as its main optimization and performance feature. Due to its impressive server-side capabilities, Next.js is able to support a wide array of performance and optimization techniques. Server-side rendering is one such technique, in which part of the React site is pre-rendered on the server, increasing load speed and efficiency.
Next.js also supports dynamically imported components, which allow developers to delay the loading of resource-heavy components until the rest of the app is loaded. Finally, Next.js offers experimental support for React Server Components, a feature that enables components to be fully rendered on the server side, resulting in zero client-side JavaScript.
Though Next.js seemingly offers a higher quantity of features for performance and optimization, it is difficult to come to a conclusive opinion on which framework offers better-quality features. This will come down to a subjective look into the needs of your product.
Throughout this article, a common theme has arisen: Next.js prioritizes a vast set of rich features that makes it suitable for virtually any use case, while Astro specifically focuses on creating the fastest website possible.
If your product doesn’t require the features offered by Next.js, you may find it too bloated and over-engineered to experience any benefit from it. For example, if your site doesn’t need server-side capabilities or AMP functionality, or if you are planning on using a framework other than React, Next.js likely isn’t the best option. Instead, if your site needs to be as fast as possible and can benefit from partial hydration, Astro is the obvious choice.
Hopefully this article has provided you with useful insights into the similarities and dissimilarities of these two frameworks, and you will now be better equipped on when to choose one over the other.
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