Next.js and PHP/Swoole/Datastar architectures faced off in a real-world mobile performance test. The hypermedia approach delivered 26× smaller payloads and 7.5× faster interactivity under 4G constraints, challenging assumptions about modern web development.

On throttled networks, JavaScript-heavy SPAs struggled with 780ms total blocking time versus 0ms for hypermedia. Lighthouse scores showed hypermedia achieving 100/100 vs SPA's 54/100 mobile performance. Critical metrics like First Contentful Paint improved 1.5× faster with server-rendered HTML.

Memory usage revealed stark differences: hypermedia maintained 1.9MB heap growth per chat interaction vs SPA's 10.4MB, reducing garbage collection pressure. Flamegraphs demonstrated hypermedia's native HTML parsing consumed 21.8× less scripting time than client-side JavaScript execution.

The Vercel AI SDK comparison validated these results against a production-grade reference implementation. With identical features and test conditions, server-side rendering proved more efficient for constrained devices. This matters for global users relying on slow connections and limited battery life.