Feed Ad
Ad formatsAn ad that runs inline in the main scrolling feed, mixed in with organic posts. On Meta and Instagram it's square (1:1) or portrait (4:5), since taller creatives claim more screen as people scroll. It has to read in an instant and work on its own, because the decision to stop scrolling happens in under a second.
Example
An Instagram feed ad at 1080×1350 (4:5) with the offer visible in the first frame, not buried in the caption.