Server-Side Rendering Migration Checklist
A migration checklist for adopting server-side rendering. It covers route classification, guarding browser-only code, server data fetching, hydration, caching, capacity, SEO, and rollback.
When to Use This Checklist
Use this checklist when moving a single-page, client-rendered application to server-side rendering (SSR), where HTML is generated on the server for the first paint. Teams adopt SSR to improve first-load performance, search engine visibility, and perceived speed on slow devices. SSR changes where code runs, so validate rendering, data fetching, and caching before the cutover.
How to Use This Checklist
Begin with a route audit. Not every page needs SSR; some are better as static pages and others can stay client-rendered. Classifying routes early keeps the migration scoped and the server load predictable.
The biggest source of bugs is code that assumes a browser. Find every direct use of window, document, or localStorage and guard it, because that code now runs on the server first. Move data fetching into server-compatible loaders so the first render has its data, and verify hydration matches exactly to avoid flicker and console errors.
Treat caching and capacity as first-class. Define TTLs and revalidation per route, then load-test the rendering tier and size it for peak. Confirm secrets stay server-side and never reach the client bundle.
What Good Looks Like
Routes are deliberately classified, browser-only code is guarded, and hydration is clean with no markup mismatches. Core Web Vitals improve or hold steady, SEO metadata renders on the server, and the rendering tier is load-tested for peak traffic. A documented rollback to client rendering exists in case SSR destabilizes production.
Common Pitfalls
The top pitfall is unguarded browser globals crashing the server render. Hydration mismatches are a close second, producing flicker and subtle bugs. Teams often forget that SSR shifts cost to a server they must now scale and monitor, leading to outages under load. Leaking server-only secrets into the client bundle is a serious and common security mistake.
Related Resources
Lean on progressive enhancement, Google Web Vitals, and performance budgets. For concrete paths, see the CRA-to-Next.js, Next pages-to-app-router, and Nuxt 2-to-Nuxt 3 migrations.