Shopify Serving Modern image formats
Using more contemporary image formats like WEBP, Shopify's Content Delivery Network (CDN) dynamically offers the best available compressed version of a requested picture as of July 2019, even if the original image is larger.
Your Shopify shop asks for a webp (which 80 percent of worldwide consumers can utilize) or whatever image format the CDN has available when you submit a PNG or JPG. Because Apple is often years behind, Safari now accounts for the majority of the remaining 20%. However, this will change with the release of the next version, which is expected later this year.
Here are some hard facts about WebP's performance in comparison to those of PNG and JPG.
For a 4k picture of the universe:.
WebP performs a poor job at compressing huge, dynamic JPGs, but it excels at reducing the size of PNGs and smaller JPGs. The PNGs seem better than the JPGs in this case.
What size should I upload?
It is imperative that you submit the largest and highest quality photos available after your theme has been correctly configured to support scaling. If your photographer provides you with 4K images, make advantage of them! Having more information in the original picture you submit, the better the image compression will operate, since it will better comprehend the desired outcome and not attempt to keep artifacts created in your previous scaling and compression.
Even more importantly, as time goes on and Shopify continues to enhance their picture compression, or new image formats become enabled, you're protected from the future.