The Facebook Square Ad size (1080×1080px)
The 1:1 square at 1080x1080 pixels is one of the most reliable formats for a Facebook feed ad. Square creative takes up more vertical space in the mobile feed than a landscape image, which means more of the screen is working for you as someone scrolls, and it also runs cleanly across the Facebook and Instagram placements that Meta bundles together in Ads Manager. Starting at 1080x1080 keeps recompression low so a product shot or headline stays crisp.
Ad images have an extra constraint that organic posts do not: Meta favors creative with little embedded text, and heavy text overlays can reduce delivery. Because of that, a square ad works best when the photo carries the message and any words are short and legible at thumbnail size. Keep your logo and call-to-action inside the central safe area so nothing important is clipped when the ad appears in different placements or gets a slight crop.
Designing at the exact pixel size also means the image lines up with the ad card, the headline, and the button Facebook stacks beneath it, so the whole unit looks intentional rather than letterboxed. If your source file is landscape or portrait, resizing it to a hard 1:1 first lets you pick the strongest crop. This tool resizes 100% in your browser with no upload, it is free, and it preserves the aspect ratio. Ad specs and text policies change often, so verify the current guidance before you spend budget.