Does imageUrlBuilder count towards Sanity API quotas?

Good news—imageUrlBuilder itself doesn't count towards any API quotas. It's purely a JavaScript utility that constructs URL strings for you. No API calls happen when you're building those URLs.

However, when browsers actually fetch and display the images using those URLs, that's when you're using resources—specifically bandwidth. The images are served through Sanity's Asset CDN at cdn.sanity.io, which is a separate system from the API CDN (Live CDN) that serves content queries.

What counts toward quotas

When images are requested:

• Bandwidth: The actual size of the image file counts toward your bandwidth quota
• Asset storage: The stored assets count toward your asset storage quota

Importantly, images served through the Asset CDN do NOT count as API CDN requests. These are different systems—the Asset CDN handles media delivery, while the API CDN handles content query responses.

Caching benefits

The Asset CDN is built on Google's global CDN infrastructure and caches assets indefinitely once processed. This means:

• The first visitor triggers bandwidth usage when the image is fetched and cached
• Subsequent visitors get the cached version without additional bandwidth impact
• The content-addressable URLs (with SHA-1 hashes) ensure aggressive caching works reliably

Plan quotas

Looking at Sanity's pricing, the bandwidth limits are:

• Free plan: Includes a baseline amount of bandwidth
• Growth plan: More bandwidth included, with the Increased Quota add-on ($299/month) bumping it to 500GB

If you're serving lots of images, the main thing to watch is your bandwidth usage, not API request counts.