I am currently working on an ecommerce website; the website is built in Magento. The website has tons of configurable products with associated simple products. For each simple product, we have different images. We are using canonical URLs on the simple product to refer to the main product (configurable product) so that Google doesn't have to index the simple products individually.
My question is this: do we need the ALT tag for every single image for simple products, or since we are using canonical URLs, do we not need ALT tags for simple product.