Why is my Sanity bandwidth so high for a static site with few images?

I can totally understand your frustration! High bandwidth usage on a static site with minimal images is definitely concerning. Based on similar cases in the Sanity community, here are the most common culprits and solutions:

Common Causes of High Bandwidth

From a very similar case that Sanity engineers investigated, here are the typical issues:

1. Image Quality Parameters (q=100)

Setting q=100 on your image URLs significantly inflates file sizes without noticeable quality improvements. Switching to q=80 can reduce bandwidth by ~30%. For example:

• q=100: 1.2 MB
• q=80: 281 KB (same image!)

2. Oversized Width Parameters

Using w=1200 or w=800 when images are displayed smaller, or when the original is already smaller than the requested size, wastes bandwidth. Only request the size you actually need.

3. Large File Assets

PDFs and other document types served through Sanity's Asset CDN can be several MB per request. If users are frequently downloading menus, brochures, or other documents, this adds up quickly.

Quick Fixes

1. Optimize your image URLs: Use q=80 instead of q=100, and set width parameters to match actual display sizes
2. Check for large files: Look at what PDFs or other assets might be getting downloaded repeatedly
3. Review your image builder configuration: If you're using @sanity/image-url, make sure you're setting sensible defaults

Debugging Tips

The bandwidth spike dropping off on weekends suggests it might be related to:

• Studio preview activity during business hours
• Automated processes or bots hitting your site
• Client editing/previewing content

Check your Sanity project's usage dashboard to see which assets are being requested most frequently. The Asset CDN caches aggressively (up to 10 MB images indefinitely), so repeated requests for the same URL shouldn't cause bandwidth issues unless the URLs are changing.

If you need help investigating further, Sanity support can look at your logs to identify the specific assets causing high bandwidth usage. Just reach out with your project ID and they can provide detailed insights into what's consuming your bandwidth.