Force-dynamic and force-static in NextJS

Introduction

Force-dynamic and force-static help Next.js decide if a page should update every time or stay the same. This makes your app faster and smarter.

When you want a page to always show fresh data, like a news feed.

When you have a page that never changes, like an About page.

When you want to control performance by choosing when to update content.

When you want to avoid unnecessary server work for static pages.

When you want to mix static and dynamic pages in your app.

Syntax

NextJS

export const dynamic = 'force-dynamic';

// or

export const dynamic = 'force-static';

Place this export at the top level of your page or layout file.

'force-dynamic' tells Next.js to always render the page on the server on each request.

'force-static' tells Next.js to render the page once at build time and reuse it for all requests.

Examples

This page will be rendered fresh on every request.

NextJS

export const dynamic = 'force-dynamic';

export default function Page() {
  return <p>Always fresh data here.</p>;
}

This page will be built once and reused for all visitors.

NextJS

export const dynamic = 'force-static';

export default function Page() {
  return <p>This page is static and fast.</p>;
}

Sample Program

This page uses force-dynamic so it updates the time on every request, showing the current server time.

NextJS

export const dynamic = 'force-dynamic';

export default function TimePage() {
  const time = new Date().toLocaleTimeString();

  return <p>Current time: {time}</p>;
}

Important Notes

Use force-dynamic for pages that need fresh data every time.

Use force-static for pages that never change to improve speed.

Setting these helps Next.js optimize your app automatically.

Summary

force-dynamic makes pages update on every request.

force-static makes pages build once and stay the same.

Use them to control when your pages update and improve performance.

Practice

1. What does the force-dynamic directive do in Next.js?

easy

A. It caches the page for offline use.

B. It makes the page build once and never update.

C. It disables server-side rendering.

D. It makes the page update on every request.

Solution

1. Step 1: Understand the purpose of force-dynamic

   This directive tells Next.js to always fetch fresh data and update the page on every request.

2. Step 2: Compare with other directives

   Unlike force-static, which builds once, force-dynamic ensures the page is never cached statically.

3. Final Answer:

   It makes the page update on every request. -> Option D

4. Quick Check:

   force-dynamic = update every request [OK]

Hint: force-dynamic means fresh page every time [OK]

Common Mistakes:

• Confusing force-dynamic with force-static
• Thinking force-dynamic disables server rendering
• Assuming force-dynamic caches pages

2. Which is the correct way to force a page to be static in Next.js using the new app router?

easy

A. export const dynamic = 'force-static';

B. export const static = true;

C. export const dynamic = 'force-dynamic';

D. export const revalidate = 0;

Solution

1. Step 1: Recall the syntax for forcing static rendering

   In Next.js app router, you use export const dynamic = 'force-static'; to make a page static.

2. Step 2: Check other options

   export const dynamic = 'force-dynamic'; forces dynamic, export const static = true; is invalid syntax, and export const revalidate = 0; controls ISR but not force-static.

3. Final Answer:

   export const dynamic = 'force-static'; -> Option A

4. Quick Check:

   force-static uses dynamic = 'force-static' [OK]

Hint: Use dynamic = 'force-static' to make static pages [OK]

Common Mistakes:

• Using force-dynamic instead of force-static
• Trying to use export const static = true
• Confusing revalidate with force-static

3. Given this Next.js page code snippet:

export const dynamic = 'force-static';

export default function Page() {
  return 
{new Date().toISOString()}
;
}

What will the page show when you refresh it multiple times?

medium

A. The date and time from when the page was first built, never changing.

B. The current date and time updated on every refresh.

C. An error because dynamic cannot be force-static.

D. A blank page because the date is not static.

Solution

1. Step 1: Understand force-static behavior

   With dynamic = 'force-static', the page is built once at build time and reused.

2. Step 2: Analyze the date rendering

   The new Date().toISOString() runs only once during build, so the date shown is fixed.

3. Final Answer:

   The date and time from when the page was first built, never changing. -> Option A

4. Quick Check:

   force-static = fixed build time content [OK]

Hint: force-static shows build time data, not live updates [OK]

Common Mistakes:

• Expecting date to update on refresh
• Thinking force-static causes errors
• Confusing force-static with server-side rendering

4. You want a Next.js page to update on every request but accidentally wrote:

export const dynamic = 'force-static';

What problem will this cause?

medium

A. The page will reload infinitely causing a crash.

B. The page will throw a syntax error and not load.

C. The page will never update and show stale data.

D. The page will update but with a delay.

Solution

1. Step 1: Identify the directive effect

   dynamic = 'force-static' makes the page static, so it does not update on each request.

2. Step 2: Understand the impact on data freshness

   The page will serve the cached static version, causing stale data to show.

3. Final Answer:

   The page will never update and show stale data. -> Option C

4. Quick Check:

   force-static = stale data if dynamic update needed [OK]

Hint: force-static stops updates, use force-dynamic for fresh data [OK]

Common Mistakes:

• Expecting syntax error from force-static
• Thinking page updates slowly instead of never
• Confusing infinite reload with static caching

5. You have a Next.js page that fetches user data and you want it statically rendered but revalidated every 10 seconds on demand to keep data fresh, also improving performance by caching for 10 seconds. Which setup correctly combines force-static and caching?

hard

A. export const dynamic = 'force-dynamic'; export const revalidate = 10;

B. export const dynamic = 'force-static'; export const revalidate = 10;

C. export const dynamic = 'force-dynamic'; export const revalidate = 0;

D. export const dynamic = 'force-static'; export const revalidate = 0;

Solution

1. Step 1: Understand force-static with revalidate

   force-static forces static rendering, but revalidate = 10 enables Incremental Static Regeneration (ISR) with 10-second caching and on-demand revalidation.

2. Step 2: Check other options

   Options with force-dynamic render dynamically without ISR caching. revalidate = 0 disables revalidation.

3. Final Answer:

   export const dynamic = 'force-static'; export const revalidate = 10; -> Option B

4. Quick Check:

   force-static + revalidate = ISR caching [OK]

Hint: Use force-static with revalidate for ISR caching [OK]

Common Mistakes:

• Using force-dynamic when ISR needed
• Setting revalidate to 0 disables revalidation
• Using force-static without revalidate for permanent static