Force-dynamic and force-static in NextJS - Performance & Optimization

Performance: Force-dynamic and force-static

MEDIUM IMPACT

This concept affects how Next.js handles server rendering and caching, impacting page load speed and responsiveness.

Rendering a page that rarely changes and benefits from caching

NextJS

export const dynamic = 'force-static';

export default function Page() {
  return <div>Static content</div>;
}

Enables caching of the page output, reducing server work and speeding up response time.

📈 Performance GainReduces server response time by 50-80%; improves LCP by caching HTML

Rendering a page that rarely changes and benefits from caching

NextJS

export const dynamic = 'force-dynamic';

export default function Page() {
  return <div>Static content</div>;
}

Forces server to render on every request, disabling caching and increasing server load and response time.

📉 Performance CostBlocks rendering for extra 100-200ms per request; increases server CPU usage

Performance Comparison

Pattern	Server Load	Caching	Response Time	Verdict
force-dynamic	High (renders every request)	No caching	Slower (blocks rendering)	[X] Bad
force-static	Low (cached output)	Yes	Faster (quick HTML delivery)	[OK] Good

Rendering Pipeline

Force-dynamic disables caching causing Next.js to render the page on every request, increasing server processing and delaying HTML delivery. Force-static enables caching, so the server can quickly serve pre-rendered HTML without reprocessing.

→Server Rendering

→Network Transfer

→Browser Rendering

⚠️ BottleneckServer Rendering

Core Web Vital Affected

LCP

This concept affects how Next.js handles server rendering and caching, impacting page load speed and responsiveness.

Optimization Tips

1Use force-static to enable caching and faster page loads for stable content.

2Avoid force-dynamic unless you need fresh data on every request.

3Check server response times in DevTools Network tab to verify caching behavior.

Performance Quiz - 3 Questions

What is the main performance impact of using force-dynamic in Next.js?

A It disables caching and causes the server to render on every request.

B It enables aggressive caching for faster loads.

C It reduces server CPU usage by caching HTML.

D It improves client-side rendering speed.

DevTools: Network

How to check: Open DevTools, go to Network tab, reload the page, and check the timing of the HTML document request.

What to look for: Look for longer server response times indicating force-dynamic; shorter times with cache headers indicate force-static.