Implementing Server-Side Rendering (SSR) in JavaScript with TanStack Router

Anton Ioffe - March 19th 2024 - 9 minutes read

In the dynamic landscape of modern web development, the interplay between enhanced user experience and efficient resource loading has never been more crucial. This article peels back the layers of Server-Side Rendering (SSR) in JavaScript, revealing the transformative potential of integrating TanStack Router into your development workflow. From grounding you in the essentials of SSR to delving into the nuts and bolts of implementing it with TanStack Router, we navigate through practical guides, optimization strategies, and debugging tips. Join us as we explore advanced techniques and best practices, mining the depths of real-world applications and projecting the trajectory of SSR's future in web development. Whether you're an experienced developer looking to refine your SSR approach or keen on mastering TanStack Router's capabilities, this article promises insights that could redefine your web development paradigm.

Section 1: The Essentials of Server-Side Rendering (SSR) with JavaScript

Server-side rendering (SSR) stands as a crucial technique in modern web development, primarily addressing the shortcomings associated with client-side rendering (CSR). One of the significant advantages of SSR is its positive impact on search engine optimization (SEO). Since the content is rendered on the server and delivered directly to the browser, search engines can crawl and index the content more effectively. This contrasts with CSR, where search engines might struggle to index content that requires JavaScript execution to render, potentially diminishing a site's visibility.

Another key benefit of SSR is the enhancement of the user experience through faster initial page load times. Unlike CSR, which can result in perceptible delays as scripts are downloaded and executed to render the application, SSR sends a fully rendered page to the client, ensuring that users can see and interact with the page's content more quickly. This speed is particularly beneficial on mobile devices and in areas with slower internet connections, helping to retain user engagement and reduce bounce rates.

JavaScript frameworks have evolved to accommodate SSR, offering developers streamlined methods to integrate SSR into their applications. These frameworks typically provide tools and conventions for defining routes, fetching data, and rendering components on the server, which can then be rehydrated on the client to become fully interactive. This approach not only leverages the strengths of SSR but also maintains the rich interactivity provided by CSR, offering a balanced solution for building modern web applications.

Focusing on the implementation of SSR, one can observe how specific JavaScript frameworks handle the rendering process. For instance, frameworks may offer distinct functionalities geared towards SSR, such as automatic code splitting, server-side data fetching, and hydration mechanisms. These features are crucial for optimizing both performance and developer experience, as they relieve developers of manually managing the intricacies of SSR.

Taking the above into consideration sets the stage for a deeper exploration of SSR using TanStack Router. As a modern routing library, TanStack Router provides a robust foundation for implementing SSR in JavaScript applications. By supporting asynchronous data loading and integrating seamlessly with server-side frameworks, TanStack Router facilitates the development of fast, SEO-friendly web applications. This examination of SSR fundamentals, advantages, and framework support provides a strong foundation from which to delve into the specifics of leveraging TanStack Router for SSR in JavaScript applications.

Section 2: Introduction to TanStack Router in the Context of SSR

TanStack Router emerges as a powerful solution in the modern JavaScript landscape, uniquely positioning itself by embracing a file-based routing approach. This paradigm shift towards using the file system structure to define application routes offers developers an intuitive and streamlined routing process. Central to its architecture is the principle of simplicity and convention over configuration, which significantly reduces the boilerplate associated with routing configurations. By leveraging the file and directory names within a project, TanStack Router automatically generates routes, embodying a form of simplicity that is both elegant and efficient.

In the realm of Server-Side Rendering (SSR), TanStack Router's architecture reveals its true strength. Its compatibility with SSR is grounded in its unopinionated nature, offering developers the flexibility to integrate it seamlessly into various SSR workflows. Unlike traditional routers that might impose specific SSR strategies, TanStack Router provides the necessary hooks and mechanisms to support SSR without dictating a rigid implementation pattern. This flexibility proves invaluable in complex applications where customized SSR logic is a prerequisite for meeting unique performance or SEO requirements.

One of the standout features of TanStack Router in supporting SSR is its modularity. By treating routes as components and leveraging the power of dynamic imports, TanStack Router facilitates code splitting out of the box. This capability is especially beneficial for SSR applications, where optimizing the payload size for initial renders is crucial. With code splitting, only the necessary code for rendering the requested route is loaded, significantly improving the time to first byte (TTFB) and overall page load performance.

Moreover, TanStack Router's ease of integration into SSR workflows is further enhanced by its support for nested routes and dynamic route parameters. This design allows for more organized and scalable routing architectures, simplifying the development of complex applications with multiple levels of routing. For SSR applications, this translates to more efficient server-side rendering processes, as the route structure closely mirrors the application's component hierarchy, facilitating a straightforward mapping between URLs and rendered content.

In conclusion, TanStack Router distinguishes itself as a formidable choice for implementing SSR in JavaScript applications. Its pioneering approach to file-based routing, combined with the principles of flexibility, modularity, and ease of integration, provides a robust foundation for developers. As SSR continues to be a vital technique for optimizing performance and SEO, TanStack Router's architecture is poised to support these endeavors, empowering developers to craft highly performant and SEO-friendly web applications with less overhead and greater efficiency.

Section 3: Implementing SSR with TanStack Router: A Practical Guide

To begin implementing SSR with TanStack Router in a JavaScript application, start by setting up your server-side environment. Assuming you're working with a Node.js server, integrate TanStack Router by installing it as a dependency in your project. You'll need to configure the router to handle requests server-side, ensuring that it can efficiently manage routing for both server-rendered and client-side pages. This setup is crucial for optimizing the initial load time and facilitating a seamless user experience.

import express from 'express';
import { renderToString } from 'react-dom/server';
import { createMemoryHistory, RouterProvider } from '@tanstack/react-router';

const app = express();

app.get('*', (req, res) => {
  const history = createMemoryHistory({ initialEntries: [req.url] });
  const content = renderToString(
    <RouterProvider router={history}>
      <App />


Next, focus on configuring TanStack Router for dynamic routes within your server-side rendering context. Dynamic routes require careful handling to ensure that the server accurately parses URL parameters and renders the appropriate component. Using createMemoryHistory, you can efficiently manage route transitions and state on the server, enabling dynamic routing that mirrors client-side behavior.

For optimizing performance, consider implementing code splitting in your server-rendered application. By leveraging dynamic imports within your route configurations, you can drastically reduce the amount of code transferred initially. This technique ensures components are only loaded when needed, improving load times significantly. Utilize Webpack or a similar module bundler to split your codebase into manageable chunks that can be dynamically loaded based on the active route.

const router = createBrowserRouter(createRoutesFromElements(
  <Route path="/" element={<Layout />}>
    <Route path="home" element={<HomePage />} />
    <Route path="about" element={lazy(() => import('./AboutPage'))} />

Lastly, to seamlessly synchronize server and client-side code, ensure that the rendered content from the server is identical to the initial client render. This is critical for avoiding hydration errors. To achieve this, serialize and pass the initial application state from the server to the client. This shared state enables the client to boot up in the same state the server rendered, creating a unified experience. Paying attention to these details elevates the SSR implementation, enhancing both performance and maintainability.

Through this structured approach, developers can harness the full potential of SSR with TanStack Router in modern JavaScript applications. Not only does this enhance the application's performance, but it also maintains a high level of maintainability and a seamless user experience. Moving forward, continuously evaluate your SSR strategy to ensure it aligns with emerging best practices and the evolving needs of your project.

Section 4: Optimizing and Debugging SSR with TanStack Router

Optimizing server-side rendering performance in a JavaScript application utilizing TanStack Router involves leveraging techniques such as code splitting, prefetching data, and employing caching strategies. Code splitting, executed through dynamic imports, enables the server to send only the necessary code for the initial route, thereby reducing the amount of data transferred on initial load. This is particularly valuable in SSR, where minimizing the time to first byte (TTFB) is crucial for improving the perceived performance. Developers can enhance this by structuring their routes and components to asynchronously load only when needed, using constructs like React.lazy for React components.

Prefetching data is another powerful optimization strategy. By anticipating the user's next move and loading data for those routes before they are actually accessed, applications can provide an illusion of instantaneous responses. With TanStack Router, this can be achieved by utilizing built-in support for data fetching and leveraging TanStack Query for sophisticated caching and preloading strategies. For instance, developers can prefetch data on link hover or during idle time, thus spreading the load over time and improving the overall user experience.

Caching, both on the client and server sides, plays a crucial role in optimizing SSR applications. Effective caching reduces the need to refetch data that hasn't changed, saving bandwidth and server resources. Server-side caching of rendered pages or API call results can significantly decrease rendering times for frequently accessed routes. Combining TanStack Router's caching mechanisms with server-side caching techniques requires careful consideration of cache invalidation to ensure data consistency and freshness.

Debugging common SSR issues requires a systematic approach to identify discrepancies between server-rendered and client-rendered content, often a source of hydration errors. Ensuring that the server and client code are in sync, particularly when features like code splitting and dynamic imports are used, is essential. Tools such as source maps and SSR-specific debugging utilities can help trace issues back to their origin. Additionally, monitoring network requests and server logs provides insights into potential bottlenecks or incorrect data fetching behaviors.

Ultimately, the pursuit of a high-quality server-rendered application with TanStack Router involves a balance between optimization strategies and maintaining a manageable complexity level. Regularly profiling the application to quantify the impact of implemented strategies, reevaluating the necessity of rendered data, and optimizing asset delivery are continuous processes. It's also crucial to stay updated with the latest advancements in SSR techniques and tools, as the JavaScript ecosystem is ever-evolving, offering new ways to enhance performance and developer experience.

Section 5: Best Practices and Real-world Considerations

Implementing Server-Side Rendering (SSR) with TanStack Router, while offering numerous benefits, presents distinct challenges that necessitate a blend of best practices and real-world savvy for optimal performance and accessibility. A critical consideration is SEO optimization, essential for ensuring your application's content is readily indexed and ranked by search engines. Leveraging SSR with TanStack Router, developers must ensure that metadata, including titles and meta descriptions, are accurately served for each route. Dynamic route data fetching and rendering strategies should be executed server-side before the initial page load to enhance content visibility, particularly for web crawlers that may not execute JavaScript.

Accessibility is another paramount concern when implementing SSR. Ensuring your application is accessible to all users, including those relying on assistive technologies, requires that rendered HTML is semantically correct and navigational elements are fully functional even without JavaScript enabled. This might involve server-side rendering of keyboard-accessible menu links and ensuring ARIA roles are appropriately assigned to dynamic content sections.

Managing application state in an SSR context introduces complexity, given the need for synchronization between server-rendered content and the client-side hydrated app. Strategies for dehydrating and rehydrating application state effectively minimize discrepancies between server and client, ensuring a seamless user experience. Storing initial state from server-side operations in a global variable for client-side pickup or employing libraries that facilitate state management across SSR environments can mitigate common pitfalls.

Challenges aside, the advantages of SSR with TanStack Router are manifold. As developers push the envelope of what's achievable, continuously evaluating performance trade-offs and refining practices for state management, routing, and data fetching become imperative. Performance profiling, both server and client-side, can illuminate bottlenecks and guide optimizations, balancing load times with dynamic capabilities.

As we forge ahead, the evolution of SSR in JavaScript frameworks, particularly with tools like TanStack Router, poses thought-provoking questions. How will emerging technologies influence server-side rendering paradigms? Can we anticipate new standards in performance optimization and accessibility compliance that will shape the SSR implementations of the future? Reflecting on these considerations not only anticipates the trajectory of web development but also invites active participation in defining its next horizon.


This article explores the implementation of Server-Side Rendering (SSR) in JavaScript using TanStack Router. It explains the benefits of SSR, such as improved SEO and faster initial page load times, and delves into the specific features and advantages of using TanStack Router for SSR. The article provides a practical guide for implementing SSR with TanStack Router, offers optimization and debugging tips, and discusses best practices and real-world considerations. The challenging technical task for the reader is to optimize server-side rendering performance by implementing code splitting, prefetching data, and employing caching strategies, while also ensuring SEO optimization and accessibility compliance.

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