Reels

Reels are 9:16 short-form video ads served between organic Reels on Instagram and Facebook. A format is a set of constraints — ratio, duration, safe area, sound expectation and user intent. The same message performs very differently across two placements because the viewer's posture is different. Building for the placement rather than resizing into it is most of the difference between fine and good. Read it next to Stories, Video Ad, Hook.

Design for the dominant placement first, then adapt deliberately: reframe rather than letterbox, keep key content clear of overlays, and assume sound is off until proven otherwise. Where a placement has a distinct native language, respect it instead of exporting one master everywhere.

Report by placement, not just campaign. A blended cost per result hides the placement subsidising or draining the set. Watch early-view retention for video placements and thumbstop for feed placements, then adjust the creative rather than only the bid. Why this matters commercially: Reels are Meta's growth format — reach is cheaper and engagement higher than feed, when the creative matches the native content style.

Xeli renders each concept into every placement's spec in one pass — correct ratio, correct safe zone, correct file requirements — so a campaign ships complete instead of arriving in fragments as resizes trickle in. In the context of ad formats & placements, that means the concept stops being something a person re-applies by hand every campaign and becomes a rule the system enforces on every asset it produces.

The recurring problems are predictable: uploading horizontal video with letterboxing; front-loading logo instead of hook; ignoring on-screen captions. Each of these is a process gap rather than a knowledge gap — which is why the fix is usually a checklist, a template or an automated rule instead of more training.