Shopify variant image not changing when a customer picks an option
For the image to change when a customer picks a variant, two things must be true: the variant must have an image assigned to it, and your theme must switch the gallery to that image. Check the assignment first, because it is the one you control directly, and only then look at the theme.
1. Assign an image to each variant
- In your Shopify admin, go to Products and open the product.
- In the Variants section, click the image icon beside the variant.
- Pick an existing product image, or click Add image to upload one.
- Confirm, then Save.
To do several variants at once, tick their checkboxes in the Variants section, open the horizontal menu, and choose Add images (or Edit images to replace existing ones).
2. One image per variant
Shopify allows only one image per variant, and variants can't use videos or 3D models. If a colour has several photos, add all of them to the product's media gallery, place them next to each other, and assign one to the variant. Customers see that image as the variant preview and can scroll the gallery for the others.
3. The theme decides what happens next
Assigning the image gives the theme the information. What it does with it depends on the theme. Some themes switch to the variant's image, some filter the gallery to the selected variant's media, and some have a setting for it in the theme editor's product page options. Open the theme editor, go to a product template, and look through the product section's settings for anything about variants or media.
4. Test a different theme
Install a fresh copy of your theme or a free theme from the Theme Store and open the same product. If the variant image switches there, the cause is in your current theme's code or settings. If it fails in every theme, the assignment in the admin is wrong or incomplete, so go back to step 1. Shopify also suggests removing recently installed apps one at a time to see whether one of them changes the gallery.
5. If a variant's image is the wrong one
Open the product and look at the image icon beside each variant. A variant can hold an image that was reused from another colour. Replace it with the right one using Edit images.
If many products have images that no longer load at all, that is a different problem. See product image not showing.