Sanity image-url crop(mode) documentation link broken - where is it?

Looking at the page you mentioned, I can see the issue! The crop(mode) parameter documentation on https://www.sanity.io/docs/image-url does have what appears to be a broken "documentation" link.

However, the good news is that all the documentation for crop modes is actually already on that same page - it's not missing, just that the link appears to be broken or unnecessary.

The crop parameter documentation is in the "The URL parameters" section. You can jump directly to it using this anchor link:

https://www.sanity.io/docs/apis-and-sdks/image-urls#crop-749d37d946b6

The documentation explains that you use crop with fit=crop to specify how cropping is performed, with these mode values:

• top, bottom, left, right: The crop starts from the edge specified (e.g., crop=top,left)
• center: Will crop around the center of the image
• focalpoint: Will crop around the focal point specified using the fp-x and fp-y parameters
• entropy: Attempts to preserve the "most important" part of the image by selecting the crop that preserves the most complex part

So while that "documentation" link may be broken, all the information you need about the crop modes is right there on the main Image transformations page. The broken link should probably just be removed since it's redundant!