Sanity image filename changes not reflecting on production site

I understand your frustration! The filename changes you're making in Sanity Studio are indeed cosmetic for the Studio interface only - they don't automatically change the actual CDN URLs that your production site uses.

Here's what's happening: When you upload an image to Sanity, it's stored with a hash-based filename (like bc4ade6a97553e67ac0e2c336f27004c8c7cd07c-1000x1000.png). This hash is based on the file's content and ensures cache efficiency - it never changes unless the actual image file changes.

The Solution: Vanity Filenames

Sanity supports what's called "vanity filenames" for SEO purposes. You can append your SEO-friendly filename to the end of the hash-based URL, and it will still work perfectly!

The format is:

https://cdn.sanity.io/images/<projectId>/<dataset>/<hashedFileName>/<your-seo-filename.png>?<params>

For example:

https://cdn.sanity.io/images/yourproject/production/bc4ade6a97553e67ac0e2c336f27004c8c7cd07c-1000x1000.png/product-name-seo-friendly.png?w=800

Implementation Steps

1. Query the original filename from your image asset documents (it's stored in the originalFilename field or you can use a custom field you've designated for SEO-friendly names)

2. Append it to your image URLs when building them in your frontend code. If you're using @sanity/image-url, you'll need to manually append the vanity filename to the generated URL.

3. Update your image URL builder to include this filename. For example:

   const imageUrl = urlFor(image).url() + '/' + image.asset.originalFilename

The beauty of this approach is that the hash portion remains unchanged (so caching works perfectly), but search engines see the SEO-friendly filename in the URL path, which is exactly what Google's image SEO guidelines recommend.

Important notes:

• You don't need to re-upload images or clear caches
• Just update how your frontend code constructs the image URLs
• All image transformation parameters (like ?w=800&auto=format) continue to work normally after the vanity filename
• The dl parameter you found is different - it forces a download with that filename, but doesn't change the URL for SEO purposes

So to answer your question directly: yes, the Studio filename changes are cosmetic, but you can achieve your SEO goals by implementing vanity filenames in your frontend code!