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Jamstack Website Optimization: Pre-rendering, CDN & SSG

Published on July 7, 2025
Last Updated on August 1, 2025

Written by

Morgan Frank - Specialist in Page Speed

Jamstack is a modern web development architecture that’s designed for speed, security, and scalability. It’s not a specific technology, but rather a way of building websites that emphasizes performance. While Jamstack sites are often inherently faster than traditional websites, there are still specific optimization techniques you can use to make them even faster.

Think of a traditional website like a factory that builds a product (the webpage) every time someone orders it. A Jamstack website is like having all the products (web pages) pre-built and ready to ship from a warehouse. This makes delivery much faster.

Before we dive into the optimization strategies, let’s review the key takeaways:

Key Takeaways

  • Jamstack Stands for JavaScript, APIs, and Markup: These are the core components of a Jamstack website.
  • Pre-rendering is Key: Jamstack sites are typically pre-rendered into static HTML files, which can be served very quickly.
  • CDN is Essential: Jamstack sites are usually deployed to a Content Delivery Network (CDN) for fast global delivery.
  • Performance is Built-In (But Optimization Still Matters): Jamstack sites are generally fast by design, but you still need to optimize images, code, and third-party scripts.
  • Focus on the Fundamentals: Many of the same optimization techniques we’ve discussed before (image optimization, minification, caching, etc.) still apply to Jamstack sites.
  • Incremental Builds: Optimize build time.
jamstack web application architecture

What is Jamstack?

Jamstack is an acronym that stands for:

  • JavaScript: Handles dynamic functionality on the client-side (in the user’s browser). This could be anything from handling form submissions to fetching data from APIs.
  • APIs: All server-side processes or database actions are handled through APIs (Application Programming Interfaces). This could be a custom API you build, or a third-party API (like a headless CMS, a payment gateway, or a search service).
  • Markup: The website is built using pre-rendered HTML files. These files are typically generated using a Static Site Generator SSG like Gatsby, Next.js, Hugo, or Jekyll.

The Core Idea: Decouple the frontend (what the user sees) from the backend (where the content and data are stored and processed).

what is jamstack

Why is Jamstack (Often) Fast?

  • Pre-rendering: The most significant advantage of Jamstack is pre-rendering. Instead of generating HTML pages on demand every time a user requests a page (like a traditional server-rendered website), Jamstack sites generate the HTML files at build time. This means the server doesn’t have to do any work to create the page when a user visits it.
  • Static HTML: Pre-rendered pages are typically static HTML files. Serving static HTML is extremely fast. There’s no database to query, no code to execute (on the server), and no templates to render.
  • CDN Delivery: Jamstack sites are typically deployed to a Content Delivery Network (CDN). CDNs have servers all over the world, so users can access your website from a server that’s geographically close to them, reducing latency and improving loading times.
  • Reduced Server Load: Because the server is primarily serving static files, the server load is significantly reduced compared to a traditional website. This makes Jamstack sites highly scalable and able to handle large amounts of traffic.

Jamstack Optimization Techniques

While Jamstack sites are often fast by default, there are still many things you can do to optimize them further:

Let’s discuss optimization techniques:

1. Image Optimization (Always!)

  • Still the #1 Bottleneck: Even on a Jamstack site, unoptimized images can be a major performance bottleneck.
  • Techniques:
  1. Use modern image formats (WebP, AVIF).
  2. Compress your images.
  3. Use responsive images (serve different sizes for different devices).
  4. Lazy load images below the fold.
  • SSG Features: Many static site generators have built-in image optimization features or plugins that can automate these tasks. For example, Gatsby has gatsby-plugin-image, which provides powerful image optimization capabilities.

2. Code Optimization

  • Minification: Minify your HTML, CSS, and JavaScript files to remove unnecessary characters and reduce file size.
  • Tree Shaking: Remove unused code from your JavaScript bundles.
  • Code Splitting: Break up your JavaScript code into smaller chunks that can be loaded on demand.
  • Critical CSS: Inline the critical CSS needed for above-the-fold content.

3. Optimize JavaScript

  • Minimize JavaScript: Even though Jamstack sites rely on JavaScript for dynamic functionality, you should strive to minimize the amount of JavaScript you’re using.
  • Defer or Async: Use the defer or async attributes on your <script> tags to prevent JavaScript from blocking rendering.
  • Framework-Specific Optimizations: If you’re using a JavaScript framework (like React, Vue.js, or Angular), follow the framework’s specific performance best practices.

4. Leverage Browser Caching

  • Caching Headers: Set appropriate HTTP caching headers (like Cache-Control) to tell the browser how long to store your website’s files locally.
  • Fingerprinting/Versioning: Add unique identifiers to your filenames to ensure browsers always get the latest version when you make updates.

5. Optimize API Calls

  • Minimize Requests: Reduce the number of API requests your website makes.
  • Request Only Necessary Data: Don’t fetch more data from the API than you actually need.
  • Parallel Requests: Fetch data in parallel where possible.
  • Client-Side Caching: Cache API responses in the browser (if appropriate) to reduce the number of requests to the server.

6. Manage Third-Party Scripts

  • Audit and Prioritize: Regularly review your third-party scripts and remove any that are unnecessary.
  • Load Asynchronously or Deferred: Use async or defer to prevent scripts from blocking rendering.
  • Self-Host (If Possible): Consider hosting scripts locally if it makes sense for performance and is allowed by the script’s terms of service.
  • Lazy Load: Delay the loading of non-essential scripts until they are needed.

7. Choose a Fast SSG

  • Build Times Matter: While the resulting website will be fast, the build times of different static site generators can vary significantly. For large websites, this can be a significant factor.
  • Consider: Hugo (Go-based) is known for its extremely fast build times. Gatsby (React-based) and Next.js (React-based) are also popular choices, but build times can be slower for very large sites. 11ty is another good option.

8. Use a Fast CDN

  • Essential for Jamstack: A CDN is practically a requirement for a Jamstack website. It’s where you’ll deploy your pre-rendered HTML files.
  • Choose a CDN with Good Global Coverage: Make sure the CDN has servers (Points of Presence) in locations that are relevant to your target audience.

9. Optimize Build Time

  • Incremental build.
  • Caching:
slow website and fast jamstack website

Conclusion

Jamstack offers a powerful architecture for building fast, secure, and scalable websites. By pre-rendering your content, leveraging a CDN, and following the optimization techniques outlined in this guide, you can create websites that deliver an exceptional user experience. While Jamstack sites are often inherently fast, remember that performance is an ongoing process. Continuously monitor your website, test different optimizations, and stay up-to-date with the latest best practices.

Shakeeb Sadikeen

The expert that experts learn from

About Author

Determined to change that, he built RapidLoad — a smart, AI-driven tool that empowers site owners to dramatically improve speed scores, enhance user experience, and meet Google’s Core Web Vitals without needing to touch a single line of code.
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