Revolutionizing React Rendering: From Hydration to Resumability

The way we render React applications is changing. Users demand faster, smoother experiences, pushing the boundaries of traditional methods. Let's explore how resumability offers a significant performance boost over hydration.

The Limitations of Hydration

Hydration, the process of turning server-rendered HTML into an interactive React app, has limitations:

• JavaScript Overhead: Requires downloading and executing significant JavaScript before interactivity. This is especially problematic on low-powered devices or slow networks.
• Double Execution: Component logic is executed twice—once on the server, once on the client—wasting resources.
• Hydration Mismatches: Discrepancies between server-rendered and client-side DOM can cause glitches and errors.

<img src="https://s3.eu-west-1.amazonaws.com/redsys-prod/articles/568049916ff1ba81238d77dc/images/teaserImage_xxxx_Shutterstock_2290245355_1747997449143.jpg" alt="From Hydration to Resumability: Rethinking React Rendering">

Resumability: A Game-Changer

Resumability offers a powerful alternative. Instead of re-executing everything on the client, it serializes application state and event handlers directly into the HTML. The client then "resumes" interactivity, loading only necessary code for specific interactions.

This minimizes JavaScript bundle sizes, dramatically improves Time to Interactive (TTI), and enhances scalability across devices.

React Server Components (RSC)

The rise of React Server Components (RSC) further enhances performance by allowing components to render exclusively on the server, reducing client-side JavaScript.

Understanding how RSC interacts with resumability is crucial for building highly performant React applications.

Conclusion

Resumability represents a paradigm shift in React rendering. By minimizing client-side JavaScript execution, it delivers significantly faster and more responsive user experiences. Embracing resumability and RSC is key to building the next generation of high-performing React applications.