What is the optimal image size and resolution?

[zigabohinc]

Hello,

I am creating a Shopify store which will contain about 2k+products (mostly jewelry). I have added about 200 products on website already and I am taking all of the photos by myself.

As of now I have uploaded about 500+ photos which are on average 200KB with resolution of 1500*1500px because I don't want the product to be too "zoomable".

My questions are:

1. What is the most optimal image size (in KB) for a website with a lot of products? Should I compress them all to be under 100KB?
2. Should only the front images be compressed? 
3. Is it okay if I use the resolution of 1500*1500px instead of 2048*2048px (recommended size) will that affect SEO and my website in any way? 
4. What is the best tool for image compression

Thank you in advance!

[dmwwebartisan · Accepted solution]

@zigabohinc 

The recommended logo size for all Shopify themes is 512 x 512 px. Check out the table below for further recommended specifications, and image best practices across our platform:

    Image type                          Dimensions                               Format             Size

Header image	2048 x 512 px	PNG or JPG	Less than 20 MB
Logo image	512 x 512 px	PNG or JPG	Less than 20 MB
Product image	Ideal size: 2048 x 2048 px Maximum size: 4472 x 4472 px	PNG or JPG	Less than 20 MB