When building web applications with Spring Boot, developers can choose between server-side rendering (SSR) and client-side JavaScript frameworks. While SPAs have gained popularity, server-side rendering offers distinct advantages for many applications.

Performance Benefits

Server-side rendering delivers immediate performance advantages. Users receive fully-formed HTML content that browsers can display instantly, without waiting for JavaScript bundles to download and execute. This results in faster initial page loads and better user experience, especially on slower networks or devices.

Client-side rendering requires multiple round trips—fetching HTML shells, downloading JavaScript, and making API calls—creating noticeable delays and loading spinners that hurt user experience.

Better SEO

Search engines favor content immediately available in HTML source code. Server-side rendered pages provide complete, indexable content from the moment they're served, ensuring better search rankings. JavaScript-heavy SPAs often struggle with SEO and require additional complexity to achieve similar search visibility.

Simplified Architecture

SSR aligns naturally with Spring Boot's ecosystem, allowing developers to use familiar tools like Spring MVC controllers, Thymeleaf templates, and Spring Security in straightforward patterns. Client-side rendering introduces architectural complexity with separate API endpoints, state management, and often duplicated validation logic between client and server.

Enhanced Security and Accessibility

Server-side rendering keeps sensitive business logic on the server, reducing security risks. It also works by default without JavaScript, providing better accessibility and progressive enhancement for users with disabilities or older browsers.

When to Choose Each Approach

Client-side rendering excels for highly interactive applications like dashboards or collaborative tools that need complex state management and real-time updates. However, for content-driven sites, e-commerce platforms, and applications prioritizing performance and maintainability, server-side rendering remains the superior choice.

Modern hybrid approaches using tools like HTMX or Alpine.js can add interactivity to server-rendered pages without the complexity of full SPAs, offering the best of both worlds.