Rumble ads video creative specs: 16:9 or 4:3, H.264 MP4, under 50 MB

Rumble's ad platform requires video creatives to be 16:9 or 4:3, H.264 MP4 only, and under 50 MB each. Details are from Rumble Ads, read 2026-10-01.

What does Rumble require for a video creative?

How do I render a 4:3 or 16:9 MP4 with Sume?

Timeline 1.0 returns an MP4 and takes any even output.width and output.height from 256 to 2160. 1920x1080 is 16:9, and 1440x1080 is 4:3. The default vertical output does not match either ratio. Timeline 1.0 (POST /v1/timeline-1.0/render) takes output.width and output.height as even integers from 256 to 2160 and output.fps of 24, 25, 30 or 60, or omits fps to match the sources. It needs an Idempotency-Key, accepts only media.sume.com sources, and returns one MP4 at $0.10 per output minute, rounded up. The unbilled POST /v1/timeline-1.0/plan previews the cost first.

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: rumble-43-001" \
  -d '{
    "audio": { "mode": "silence", "duration_seconds": 20 },
    "output": { "width": 1440, "height": 1080, "fps": 30 },
    "video": [
      { "source_url": "https://media.sume.com/artifacts/artf_demo/shot.mp4",
        "start": 0, "duration": 20, "fit": "cover" }
    ]
  }'

Is the output H.264?

Sume's Timeline docs say it returns an MP4 but do not state the codec. Video trim's exact precision is documented as libx264 and yuv420p, but trim is not the render path. Confirm the codec with a local tool before you submit.

How do I keep a clip under 50 MB?

Sume lists no bitrate field, so the lever is length and resolution. Video trim cuts a shorter clip and conforms output size and frame rate on the way out. Then check the size yourself, because Video inspect does not report it.

Are there other Rumble limits?

Probably. Rumble's creative page may list duration or placement rules. The facts above are the only ones I read from it, so check it before you upload.