Can a 4:5 or 2:3 video run in Google Ads? What the specs allow

Yes. Google's spec page lists 16:9 (horizontal), 9:16 (vertical) and 1:1 (square) as the primary aspect ratios, and it also names 4:3 for horizontal and 2:3 and 4:5 for vertical as acceptable. A second Google page says "Aspect ratios between these settings are allowed." So a 4:5 or 2:3 file is within what the pages permit, though 9:16 and 1:1 remain the recommended pair.

If you want to export one of those ratios from Sume Timeline, you set output.width and output.height yourself, and both must be even integers between 256 and 2160. This post gives the exact sizes that satisfy that rule.

What each Google page says

"About video ad specs" states: primary 16:9, 9:16 and 1:1; also acceptable 4:3 (SD) for horizontal, and 2:3 and 4:5 for vertical. The recommended resolution is 1080p: 1920x1080 horizontal, 1080x1920 vertical, 1080x1080 square. Minimums are 1280x720, 720x1280 and 480x480.

"Use square and vertical video to engage mobile customers" is where the in-between sentence lives, and the same page recommends the three primary ratios for Video and App campaigns. Neither page says that an in-between ratio performs the same as a primary one, so test before you replace a 9:16 master.

Even-integer sizes for each ratio

The Timeline schema takes even integers only, so each size below is derived by holding the 1080 edge and rounding the other edge to an even number. The 4:3 row lands at 1440x1080 because 1080 x 4 / 3 = 1440 exactly. The 2:3 row is 1080x1620 because 1080 x 3 / 2 = 1620. The 4:5 row is 1080x1350 because 1080 x 5 / 4 = 1350.

Every row is at or above the Google minimum for its orientation, and every edge is inside the 2160 maximum.

The render request

Only output changes between ratios. The fit value decides what happens when the source frame is a different shape: cover crops to fill, contain adds bars, blur fills the bars with a blurred copy of the slot. The sample renders a 4:5 file.

A clip under one minute bills one Timeline minute at $0.10 (documented public rate, TIMELINE_PUBLIC_PRICING; confirm in GET /v1/catalog).

curl -X POST https://api.sume.com/v1/timeline-1.0/render \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: ratio-4x5-001" \
  -d '{
    "audio": {
      "url": "https://media.sume.com/artifacts/artf_demo/voice.wav",
      "duration_seconds": 20
    },
    "video": [
      {
        "source_url": "https://media.sume.com/artifacts/artf_demo/hero.mp4",
        "start": 0,
        "duration": 20,
        "fit": "blur"
      }
    ],
    "output": { "width": 1080, "height": 1350 }
  }'

Does the ratio change what YouTube calls it?

Separately from ads, YouTube's three-minute Shorts page says a video with "a square or vertical aspect ratio up to three minutes in length" is categorised as a Short for standard channels uploaded on or after October 15, 2024. A 4:5 or 2:3 file is taller than square, so the ratio is not the obstacle; length is. Keep an organic upload at or below 180 seconds if you want it to be a Short.

That rule applies to uploads to YouTube, not to ads, so do not assume an ad file is classified the same way.

Mistakes to avoid

The most common mistake is sending an odd dimension. Timeline refuses sizes that are not even integers in the 256 to 2160 range, because yuv420p video needs even sides. If you compute 4:5 from a height of 1920, you get 1536, which is fine, but 4:5 from a width of 1081 is not. Start from the 1080 edge and the table above.

The second mistake is treating "acceptable" as "recommended". Google's primary list is 16:9, 9:16 and 1:1, and its in-between sentence is a permission, not a performance claim. Keep a primary-ratio file in every campaign, and add the in-between file as a test arm.

The third mistake is forgetting the minimums. A 4:5 file at 576x720 may be a fine social crop but sits below the 720-pixel vertical minimum Google lists for its orientation. Render at 1080 on the short edge and let the platform scale down.

Finally, remember that Sume does not expose bitrate or codec controls: Timeline refuses codec, crf and filtergraph keys, because the server compiles ffmpeg itself. If a spec page asks for a particular codec or bitrate, check the delivered file rather than trying to set it in the request. The ratio and size are the parts you control, and those are the parts the Google pages constrain.