Meta image expansion or a native 9:16 Sume image for Reels ads?

Use Meta's image expansion when you have a 1:1 or 4:5 image and want 9:16 delivery with no extra work, and generate a native 9:16 image on Sume when composition matters. Meta's Reels ads page says image expansion uses generative AI to expand a creative to 9:16 (read 2026-10-10). Sume's Image API lists 9:16 as an aspect ratio, so you can ask for that shape from the start.

What Meta says

The page also reports that 9:16 with audio and the safe zone gave a 34.5% lower cost per result and 2x delivery, and describes safe zones of 14% at the top, 35% at the bottom and 6% on each side.

Where expansion fits

Expansion fills the new area around your image. You do not control what it draws there, and the result can differ run to run. That suits a product shot on a plain background, a fast test, or a catalog of many images.

Expansion also has a practical advantage: it needs no new asset. If your feed ads already run as 4:5 images, turning on expansion for Reels placements costs you a setting rather than a production job. The tradeoff is that you review what it generated per placement, and a legal or brand-sensitive layout may need a human check either way.

Where a native 9:16 image fits

On Sume you pick the aspect ratio before generation, so the model composes for the vertical frame. For an edit, aspect_ratio auto matches the reference image. Put the subject in the middle band so the 14% top and 35% bottom zones stay clear of key content.

The Image API does not serve explicit pixel sizes in v1, so you ask for a ratio and read the result's size from the response. Meta's page lists 1440x2560 for Reels ads; compare what you get before you assume it matches.

Sume's image edit route also lets you start from an existing 4:5 or 1:1 reference and ask for 9:16. That is a regeneration, not a pixel-preserving extension, so the model may change details of the original. If the original must stay exact, compose it onto a vertical canvas yourself, or use Timeline 1.0 with fit blur to place a still inside a 1080x1920 frame with a blurred fill. That is a video render, for $0.10 per ceil minute, so it suits a short Reels video, not a still image ad.

• Many images, plain backgrounds, speed first: let Meta expand.
• One hero image, faces, text in the picture or a strict layout: render 9:16 natively.
• Either way, keep text out of the top 14% and bottom 35%.

Decide with a small test

Take one image and run both routes. Expand it in Ads Manager, and generate a native 9:16 version on Sume from the same brief. Compare both in the Reels preview with the safe-zone overlay. Meta's 34.5% figure is about the 9:16, audio and safe-zone package, not about expansion versus native, so it does not decide this choice for you.