Carousel vs single image ads on Facebook: which to run

Short answer: neither format wins on its own. A single image works when one picture and one line carry the sale. A carousel works when you have several things worth showing: different products, the colors of one product, or steps that only make sense in order. If you're not sure which you have, run one of each as separate ads in the same ad set and let cost per purchase decide after about a week.

I work on Everix. The question comes up more now that static image ads are back in fashion, and "static" covers both formats. They do different jobs.

What Meta says a carousel is

• A carousel shows 2 to 10 images or videos in one ad. Each card has its own headline, description, link and call to action.
• People swipe on a phone, or click the arrows on a computer, to see the next card.
• Highlight carousel card is on by default: Meta orders the cards by how they perform, on Facebook Feed, Instagram Feed and Instagram Stories. Everywhere else, the cards show in the order you set.
• For videos inside a carousel, Meta recommends square (1:1). Carousels built from a catalog can also show 4:5.
• A catalog carousel needs at least 2 items that are in stock, not rejected and not variants of the same product. Below 2, Meta says the ad turns into a single image ad or stops running.

When a single image is the better bet

If the store sells one hero product, or the ad is about one offer, the first card does the selling either way, because it's the only card everyone sees. Cards two to ten cost time to make without adding a reason to buy. Put that time into a second single image with a different angle instead, so you're testing two reasons to buy rather than one reason spread over five cards.

When a carousel is the better bet

• You sell a range. Show a different product on each card and link each card to that product, as Meta suggests. A smaller store can send every card to the collection page instead.
• One product comes in options people care about, like colors, sizes or scents. Showing them answers "does it come in..." before the click.
• The product needs steps to make sense: the problem, the product, the result. If the order is the point, turn Highlight carousel card off, or Meta may show the result first.

How to test one against the other

Put one single image ad and one carousel in the same ad set, with the same offer and the same landing page, so the format is the only difference. Leave both for about a week and compare cost per purchase (or cost per lead), not click-through rate. CTR tells you who was curious, not who bought, and a high CTR can hide a low link CTR.

Then open the carousel's breakdown: in Ads Manager, choose Breakdown, then By action, then Carousel card. If one card takes most of the clicks and the rest get almost none, that card is your next single image ad.

Run a single image when one picture can sell it, and a carousel when you have several things worth showing. Test both in one ad set and judge them on cost per purchase, not CTR.

How Everix handles it

Everix runs single image and video ads; it doesn't build carousels. Instead of one carousel with five products, you upload the five images as five ads in the same lane, and each one gets its own cost per purchase instead of sharing one ad's average. Everix watches them around the clock and makes a media buyer's calls: which creative is tired, which placement is burning money, which winner has earned more budget. For how many creatives a budget can really test at once, see why only one ad is spending.