Your best bet would be the Photo Resize app by PixC.
Costs a couple cents per image (one-time fee). Usually costs less than $20 to do an entire store.
Hope this helps! :)
Thanks for the recommendation!
I have another question. Let's say I use the app to resize my images. A month from now if I had on more products and pics, will I have to pay for the app to resize my entire store again, or will it only apply to the new pictures I just added?
I hope my question makes sense?
It should only charge for new images added (you shouldn't have to pay for images that are already edited).
Hey Tay Jewels, you can also try "On Demand Photo Editing" app by PixoPal
The app lets you browse your product photos and select the ones you need to edit or resize.
You may also create a template for the sizing, and can keep it uniform for all your products. This may become useful for your new product images