CDN vs. Local Hosting for Static Sites: Pros & Cons
Introduction: Where Should Your Files Live?
When building a static website with a framework like Astro, Next.js, or Hugo, you have two primary options for serving your static assets (images, CSS, JavaScript):
- Local Hosting: Placing the assets directly within your project’s repository (e.g., in the
public/
orsrc/assets/
folder). They are served from the same domain as your website. - CDN Hosting (Content Delivery Network): Uploading your assets to a separate service (like Cloudflare R2, AWS S3, or a dedicated image CDN) and linking to them from your site.
While modern hosting platforms like Vercel and Cloudflare Pages have blurred the lines by providing a CDN by default, understanding the core trade-offs is still crucial for optimizing performance and cost.
Local Hosting: The Simple & Modern Default
With modern static site hosting platforms, “local” hosting is a bit of a misnomer. When you deploy your site to Vercel, Netlify, or Cloudflare Pages, your assets are automatically distributed across their global CDN.
Pros:
- Simplicity: This is the easiest approach. Just drop files into your project and link to them. There’s no separate build step or service to manage.
- No Extra Cost: Hosting is included with your plan. There are no surprise bandwidth bills from a separate provider.
- HTTP/2 & HTTP/3 Benefits: Serving assets from the same domain allows the browser to reuse a single connection, which is highly efficient with modern protocols like HTTP/2 and HTTP/3, eliminating the overhead of new DNS lookups and handshakes.
- Better for SEO (Arguably): Keeping images on your own domain ensures you get the full “SEO juice” from Google Images traffic. There’s no risk of search engines attributing your images to a third-party domain.
Cons:
- Limited Transformation: You don’t get advanced features like on-the-fly image resizing, format conversion (e.g., auto-serving AVIF), or device-specific optimization that dedicated CDNs offer.
- Build Times: If you have thousands of images, they can bloat your repository and increase build times.
- Git Repository Size: Large media files are not ideal for Git. Services like Git LFS (Large File Storage) can help but add complexity.
Verdict: For most small to medium-sized static sites (blogs, portfolios, marketing sites), local hosting is the best choice. The simplicity and performance benefits of same-domain hosting on a modern platform outweigh the cons.
Dedicated CDN Hosting: For Scale and Advanced Features
This approach involves storing your assets on a cloud storage service (like AWS S3 or Cloudflare R2) and serving them through a CDN.
Pros:
- Advanced Image Optimization: Services like Cloudinary, Imgix, or Cloudflare Images can automatically serve the best image format (AVIF/WebP), resize images based on the user’s screen size, and apply advanced compression, all on the fly. This can lead to significant performance gains.
- Decoupled from Your Build: Your site’s repository remains small and your build process is fast, as you’re just linking to external assets. This is ideal for sites with a large amount of user-generated content.
- Potentially Cheaper at Massive Scale: For sites with terabytes of traffic, the per-gigabyte cost of a dedicated CDN might be lower than the top-tier plans of a static hosting provider.
Cons:
- Complexity: It introduces another service to manage, configure, and pay for. You need to set up a pipeline for uploading assets.
- Cost: While often cheap to start, bandwidth costs can be unpredictable and add up quickly if your site gets a lot of traffic.
- Performance Overhead: Serving assets from a different domain requires the browser to perform a separate DNS lookup and connection handshake, which can slow down the initial render, especially on slow networks.
- SEO Complications: You need to be careful to ensure search engines correctly associate the images with your domain. Using a CNAME to serve the CDN content from a subdomain (e.g.,
cdn.yourdomain.com
) is a common best practice.
Verdict: A dedicated CDN is best for large-scale applications, sites with user-generated content, or when you absolutely need advanced, on-the-fly image transformations that your hosting platform doesn’t provide.
The 2025 Recommendation: Start Local, Scale When Needed
For a new project, the answer is clear: start with local hosting.
- Choose a modern static hosting provider like Vercel, Netlify, or Cloudflare Pages.
- Keep your images and assets within your project repository.
- Optimize your images before you commit them. Use a tool like our Image Compressor to reduce file sizes and an Image Converter to switch to modern formats like WebP.
- Implement responsive images using the
<picture>
tag orsrcset
attribute to serve different sizes.
This simple, cost-effective setup will be more than performant enough for 95% of static websites. You should only consider moving to a dedicated CDN when you face specific scaling challenges, such as a massive media library slowing down your builds or the need for complex, real-time image manipulations.