Meta lists 1440x2560 for Reels ads; Sume timeline stops at 2160

Meta's Instagram Reels video ad page lists a resolution of 1440 x 2560, and Sume's Timeline 1.0 accepts output.width and output.height from 256 to 2160. So a timeline render cannot produce a 2560 pixel edge. The same Meta page lists a minimum width of 250 pixels for clips under 30 seconds and 500 pixels for longer ones, which a 1080x1920 file clears easily.

Meta's numbers

From the Meta Ads Guide (read 2026-10-05): aspect ratio 9:16, resolution 1440 x 2560, duration 0 seconds to 15 minutes, MP4 or MOV, 4 GB maximum, minimum width 250 pixels under 30 seconds and 500 pixels at 30 seconds or longer. The excerpt I read does not say whether a smaller file is rejected or merely scaled, so I do not claim either.

What the timeline can and cannot draw

output.width and output.height are even integers from 256 to 2160 in the Timeline 1.0 docs, so 1440 wide is fine but 2560 tall is not. The default output is 1080x1920. The largest 9:16 frame the timeline can make is 1215x2160 if you take the height limit, rounded to an even width: 2160 x 9 / 16 = 1215, and even integers mean 1214 or 1216 are the nearest legal widths, with a small aspect error. I would not chase that.

Two paths

Two honest paths exist. The first is to render 1080x1920, which is well above Meta's minimum widths, and accept that it is smaller than the listed 1440 x 2560. The second is to use a model clip that already has a bigger frame. On the catalog, gemini-omni-flash-1.1 lists 4K in 16:9 or 9:16 per the Video Router docs, but the docs do not state the 4K vertical pixel size, so measure the result with video inspect before you rely on it. Passing a model file straight to Meta, without a timeline render, avoids the 2160 limit entirely.

Measure before you upload

Run video inspect on the finished file and read the still's width and height:

curl -X POST https://api.sume.com/v1/video-inspect \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: reel-size-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/ad.mp4",
    "frames": { "at": [1], "format": "jpeg", "max_edge": 2160 }
  }'

Reading the numbers

max_edge is 64 to 2160 with a default of 768, so set it to the source edge if you want a still at full size, and the limit is 24 stills per call. The frames array in the result gives t, url, width and height.

Where to decide

The table of Meta numbers and Sume limits does not contradict itself: Meta describes what an ad should be, and Sume describes what a timeline can render. If the final file must be larger than 2160 on an edge, do not route it through a timeline.

Test one file

A practical way to settle this for your account is a small test. Render one ad at 1080x1920 and upload it to a Reels placement in a draft campaign, then read what Ads Manager says about the file. If it accepts the file and shows no quality warning, you have your answer for that placement without depending on a guess about how Meta treats smaller frames.

Keep the two columns apart

Do not infer more from the table than it says. The Meta column is the vendor's published spec read on 2026-10-05, and the Sume column is from the Timeline 1.0 docs. The two describe different things: one is the target, the other is a render limit. Keep them separate when you brief a team, and write down which file you actually shipped.

Reuse the master

If your pipeline already makes 1080x1920 files for other placements, reusing the same master for Reels removes one export. That is a real saving when you run many ad variants through the same timeline plan.

The takeaway

Render 1080x1920 for a Reels ad unless you have a reason to chase the listed 1440 x 2560, and always read the real size of the file you upload.