LTX-2.5 Pro at 4K: $0.39 a second, 10 s cap, vs Omni 4K on Sume

LTX-2.5 Pro is priced from $0.12 to $0.39 per second, with the $0.39 end at 4K, and its clips top out at 10 seconds (read 2026-10-07). A 10-second 4K clip is therefore $3.90 on the LTX API. Sume does not list an LTX model; the 4K row it does list is Gemini Omni Flash 1.1, which comes to $0.375 per second and $3.75 for 10 seconds.

The two prices are close, but the models differ, so treat this as a budgeting check, not a quality ranking.

LTX-2.5 rates and limits

LTX publishes two tiers for LTX-2.5: ltx-2-5-fast and ltx-2-5-pro. Text-to-video and image-to-video share one price list. The fast tier can run up to 20 seconds at lower frame rates, and the pro tier is capped at 10 seconds at every resolution and frame rate.

What Sume lists at 4K

Gemini Omni Flash 1.1 (gemini-omni-flash-1.1) accepts 3 to 10 seconds at 360p, 720p, 1080p, and 4K in 16:9 or 9:16, with native synced audio. Its provider list is $0.30 per second at 4K (fal, 2026-08-28), and Sume bills list times 1.25, which is $0.375 per second.

That makes a 10-second 4K clip $3.75 on Sume, $0.15 less than LTX-2.5 Pro and $0.75 more than LTX-2.5 Fast at 4K ($3.00 for 10 seconds).

Choosing between them

Check what a Sume key can call with GET /v1/videos/models before you plan a 4K run, because the catalog changes and limits differ per model.

• Need LTX specifically, or its open-weight license and local runs: use LTX directly. Sume has no LTX id and no LoRA field.
• Need one hosted key, async jobs, webhooks, and a balance across video, image, and audio: Omni Flash 4K is the Sume row.
• Need more than 10 seconds at 4K from one call: neither Pro nor Omni goes past 10 seconds. Fast can reach 20 at lower frame rates.
• Need vertical 4K: LTX lists 2160x3840 portrait, and Omni accepts 9:16.

A 4K request on Sume

Omni takes 4K as its resolution value on Sume, and the poll response reports the Sume billable amount in usage.cost.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: omni-4k-demo-001" \
  -d '{"model": "gemini-omni-flash-1.1", "prompt": "Slow push-in on a ceramic mug of coffee, steam rising", "resolution": "4K", "duration": 10, "aspect_ratio": "16:9"}'

The honest summary

If the brief says LTX-2.5, you will not get it through Sume today. If the brief says 4K with sound and a 10-second clip, Sume can do that at $3.75. For the longer analysis of native 4K, read LTX-2.5 4K against Omni 4K.