React, Rendering, Performance - Nadia Makarevich - performance.now() 2025

In the React community, we keep hearing that React Server Components (RSC) are the future. That they're supposed to be The Best for performance. And just the best in general. But is it true? What are those Server Components anyway? There is also Server-Side Rendering (SSR), is it the same? What about Client-Side Rendering (CSR), is it not cool anymore? So many questions! To answer them, I went slightly crazy and implemented one app in three different ways: using CSR, SSR, and RSC. Then, measured the difference. And now, ready to show it to you. In this talk, we'll take a look at the different rendering techniques in React, explore how they work, how they influence initial load numbers, look at what React Server Components bring to the table performance-wise, and dig into the cost of it. Slides: https://drive.google.com/file/d/18MURNelPY6RJmw6ashsk3mfDgkDX8sf_/view *** A session from performance.now(), the web performance conference. Each November in Amsterdam; see https://perfnow.nl for more information. Conference announcements in your inbox? https://perfnow.nl/subscribe