Next.js - Changing the Web

What is Next.js?

Next.js is a React framework designed for building full-stack web applications. It extends the capabilities of React by providing structure and additional features needed for production-ready applications.

With Next.js, you use standard React components to build user interfaces. The framework then adds capabilities like routing, API routes for backend logic, data fetching mechanisms, and built-in optimizations.

One of the key benefits is that Next.js automatically handles complex configurations for tools like bundlers and compilers, allowing developers to focus more on building their product and shipping quickly.

It is known for enabling the creation of high-quality, interactive, dynamic, and fast React applications, and is used by some of the world's largest companies.

Core features include:

• Built-in Optimizations: Automatic optimizations for elements like images, fonts, and scripts to improve performance and user experience.
• Data Fetching: Flexible options for fetching data, supporting both server and client-side approaches, including making components asynchronous.
• Server Actions: A way to run server-side code directly from React components, simplifying data mutations and invalidation.

Next.js is a powerful and adaptable React framework for building fast, full-stack web applications. It provides the necessary building blocks to create high-quality web applications using React components. Think of React as a library for building user interfaces, and Next.js as the framework that adds structure, features, and optimizations on top of React. It handles underlying tools like bundlers and compilers automatically, allowing developers to focus on building their product.

Full-Stack Apps

Next.js is considered a full-stack framework because it provides tools for both frontend and backend development within a single codebase. This includes features like API routes, which allow you to build server-side logic and database operations without needing a separate backend server.

Top 3 Optimizations

Next.js includes several built-in optimizations to improve application speed and user experience. Here are some key ones:

• Image Optimization: The built-in next/image component automatically optimizes images by lazy loading and resizing them based on the device.
• Font Optimization: The next/font feature optimizes web fonts, improving performance and privacy by self-hosting Google Fonts.
• Code Splitting: Next.js automatically splits code, so pages only load the necessary JavaScript, improving initial load times. You can also use dynamic imports for further optimization.

Data Fetching

Next.js offers various data fetching methods to handle different scenarios, including:

• Client-Side Rendering (CSR): Data is fetched in the browser after the page loads, typically using hooks like useEffect.
• Server-Side Rendering (SSR): Pages are rendered on the server for each request, fetching data before the page is sent to the client. This is good for dynamic content and SEO. This is often done using the getServerSideProps function.
• Static Site Generation (SSG): Pages are pre-rendered at build time with data, resulting in fast loading static HTML files. This is achieved using the getStaticProps function.
• Incremental Static Regeneration (ISR): Allows updating static content after the site is built without a full rebuild.

Server Actions

Server Actions are asynchronous functions that run on the server in response to client interactions. They can be used for handling form submissions and data mutations directly on the server, reducing client-side JavaScript. They can be defined using the "use server" directive.

Project Setup

The quickest way to start a new Next.js project is by using create-next-app. You can run npx create-next-app@latest in your terminal and follow the prompts to configure your project with options like TypeScript, ESLint, and Tailwind CSS.

Fast Web Apps

Next.js is designed to help build fast and performant web applications through features like server-side rendering, static generation, and automatic code splitting. These contribute to improved loading times and user experience.

Used by Companies

Many companies use Next.js for their websites and applications. Some well-known examples include Netflix, Nike, TikTok, Uber, and GitHub.

Focus on Product

By abstracting away complex configurations for things like bundling and routing, Next.js allows developers to concentrate on building the core features and logic of their application, rather than spending time on setup and tooling.

Full-Stack Apps

Next.js serves as a robust React framework designed for building full-stack web applications. This means you can develop both the user interface (frontend) using React components and the server-side logic (backend) within a single, unified project structure.

Traditionally, building full-stack applications involved separate projects for the frontend (like a React app) and the backend (using frameworks like Node.js with Express, Django, or Ruby on Rails), requiring developers to manage multiple servers and deployment processes.

Next.js simplifies this by providing features that bridge the gap between the client and the server. It allows you to colocate your frontend components and backend code, making development and maintenance more streamlined.

Key features in Next.js that enable full-stack development include:

• Data Fetching: Next.js offers flexible ways to fetch data, whether on the server before the page is rendered (Server-Side Rendering or Static Generation) or on the client-side. This is crucial for dynamic applications that need to display up-to-date information.
• Server Actions: This feature allows you to run server-side code directly from your React components. It simplifies data mutations and server logic by enabling direct function calls, potentially reducing the need for separate API routes for certain operations.

By integrating these capabilities, Next.js empowers developers to build complete applications more efficiently, focusing on the product rather than managing complex infrastructure setups.

Built-in Optimizations

Next.js comes with several built-in optimizations designed to enhance the performance and user experience of your web applications right out of the box.

These include automatic optimizations for images, fonts, and scripts. These features work behind the scenes to ensure that your application loads quickly and efficiently, contributing to better Core Web Vitals scores and overall improved user experience.

By automatically handling common performance bottlenecks, Next.js allows developers to focus on building their product rather than spending excessive time on manual performance tuning.

Data Fetching

Handling data is a core part of building any web application. Next.js provides flexible and powerful ways to fetch data, allowing you to choose the strategy that best suits your needs, whether it's fetching data on the server or the client.

One of the key features in Next.js is the ability to make your React components async. This allows you to use the await keyword directly within your components to fetch data right where it's needed. This simplifies the code and keeps data requirements close to the components that render them.

Server and Client Fetching

Next.js supports both server and client data fetching.

• Server Data Fetching: Fetching data on the server before the page is rendered and sent to the client. This is beneficial for SEO (Search Engine Optimization) and initial page load performance as the HTML is already populated with data. Async Server Components are a primary way to achieve this.
• Client Data Fetching: Fetching data directly in the user's browser after the initial page load. This is useful for dynamic content, user-specific data, or when data isn't required for the initial render. You can use standard React patterns like the useEffect hook in Client Components or libraries like SWR or React Query for more advanced caching and state management.

The choice between server and client fetching depends on factors like data freshness requirements, user interactivity, and SEO considerations. Next.js gives you the tools to implement either or even combine both approaches within the same application.

Server Actions

Related to data handling, Next.js introduces Server Actions. Server Actions allow you to run server-side code directly from your React components, often used for handling form submissions and data mutations. They can simplify data updates and revalidation by allowing you to perform server logic and update the UI in a single network roundtrip, potentially replacing the need for explicit API routes for simple data operations.

By providing these different data fetching mechanisms and tools like Server Actions, Next.js makes it efficient to build dynamic and responsive web applications with React.

Server Actions

Server Actions are a feature in Next.js that allow you to run server-side code directly from your React components. They are asynchronous functions that can be used in both Server and Client Components. This enables you to handle tasks like form submissions and data mutations on the server, reducing the need for separate API routes in many cases.

How They Work

Server Actions are defined as asynchronous functions and marked with the 'use server' directive. When a Server Action is invoked from the client, Next.js handles it as a POST request to the server. This process is abstracted away, so you can call the server function directly in your component code.

Benefits of Using Server Actions

• Reduced Client-Side JavaScript: Since Server Actions run on the server, the code is not included in the client bundle, leading to smaller JavaScript payloads and faster initial page loads.
• Simplified Data Mutations: You can perform direct data mutations on the server without building and managing separate API endpoints.
• Improved Performance: By handling server-side logic on the server, you reduce the load on the client and can improve overall application responsiveness.
• Enhanced Security: Sensitive operations can be kept on the server, enhancing security.
• Integration with Caching and Revalidation: Server Actions integrate with Next.js's caching and revalidation architecture, allowing you to update the UI and data in a single roundtrip after a mutation. You can use functions like revalidatePath and revalidateTag to refresh cached data.
• Support for Progressively Enhanced Forms: Forms that use Server Actions can remain functional even when JavaScript is disabled.

Use Cases

Server Actions are ideal for scenarios where you need to perform server-side logic in response to user interactions, such as:

• Handling form submissions.
• Mutating data in a database.
• Performing server-side data fetching that is tightly coupled with a component.

Considerations

While Server Actions offer many advantages, it's important to note that they are implemented as POST requests. This means they are not ideal for data fetching that requires caching, where GET requests are typically more suitable. For fetching data that can be cached, traditional server-side rendering or other data fetching methods might be a better fit. Additionally, Server Actions execute sequentially, which might impact performance if you need to make multiple independent server requests in parallel.

Project Setup

Before you start building with Next.js, you need to set up your project environment. A key requirement is having Node.js installed on your system. Ensure you have version 18.18 or later. Next.js is supported on macOS, Windows (including WSL), and Linux operating systems.

The recommended and quickest way to create a new Next.js application is by using create-next-app . This command-line tool sets up everything you need automatically.

To create your project, open your terminal or command prompt and run the following command:

npx create-next-app@latest

Running this command will start an interactive process where you'll be asked several questions to configure your project. These prompts help tailor the initial setup to your preferences and project needs.

Some of the typical questions you'll encounter include:

• What is your project named? - This sets the name of your project directory.
• Would you like to use TypeScript? - Choose whether to include TypeScript for type safety.
• Would you like to use ESLint? - Configure ESLint for code linting.
• Would you like to use Tailwind CSS? - Add the Tailwind CSS framework for styling.
• Would you like your code inside a src/ directory? - Organize your main code files within a src directory.
• Would you like to use App Router? (recommended) - Select the App Router, which is the newer and recommended routing approach in Next.js.
• Would you like to use Turbopack for next dev? - Opt into using Turbopack, a faster build engine for development.
• Would you like to customize the import alias (@/* by default)? - Define a custom alias for your import paths.

After answering these prompts, create-next-app will install the necessary dependencies and set up the initial project structure based on your choices. Once completed, you will have a new Next.js project ready for development.

Fast Web Apps

Building fast web applications is crucial for a good user experience and better search engine rankings. Next.js, as a React framework, provides features that help developers create performant applications.

One way Next.js helps is through built-in optimizations. This includes automatic optimizations for images, fonts, and scripts. These optimizations contribute to improved user experience and better Core Web Vitals scores.

By handling aspects like code splitting and server rendering, Next.js reduces the amount of JavaScript the browser needs to download and execute initially, leading to faster load times. This allows you to focus on building your product without getting bogged down in complex performance configurations.

Used by Companies

Next.js is a widely adopted React framework chosen by many companies, including some of the world's largest organizations. It provides a robust foundation for building web applications with React components.

Companies leverage Next.js for several reasons. Its built-in features and optimizations, such as automatic image, font, and script optimizations, contribute to improved user experience and better Core Web Vitals. The framework's support for both server and client data fetching, including features like Server Actions, allows for efficient data management and streamlined application development. By handling lower-level configurations and tools automatically, Next.js enables development teams to focus more on building the actual product and shipping features faster. This makes it a suitable choice for both individual developers and larger teams building interactive, dynamic, and fast React applications.

Focus on Product

Next.js is designed to help developers concentrate on building the core features of their web applications rather than spending excessive time on configuration and setup.

As a React framework, it provides a structured approach to developing user interfaces using React components. Everything needed to build effective web products is included.

It automatically handles lower-level aspects like bundlers and compilers, allowing developers to focus on the product itself and ship quickly.

Features such as Automatic Image, Font, and Script Optimizations are built-in to improve user experience and Core Web Vitals. Data fetching is flexible, supporting both server and client methods by making React components asynchronous. Server Actions simplify backend interactions, enabling server code execution by calling functions directly and efficiently updating the UI.

By providing these features and handling common complexities out of the box, Next.js allows development teams to be more productive and direct their energy towards innovating and refining the user experience of their application. This is why it's used by many large companies.