Supported resolutions, frame rates, and durations for the API
The LTX API supports output resolutions from 1080p up to 4K, in both landscape and portrait orientations. Available frame rates and durations vary by model and resolution.
When you make a generation request, you set the output resolution using exact pixel dimensions — for example, 1920x1080 for 1080p landscape. The available options, frame rates, and durations differ between LTX-2.3 Fast and Pro.
Supported resolutions
| Label | Landscape (16:9) | Portrait (9:16) |
|---|---|---|
| 1080p | 1920x1080 |
1080x1920 |
| 1440p | 2560x1440 |
1440x2560 |
| 4K | 3840x2160 |
2160x3840 |
Frame rates and durations by model
Durations are not arbitrary — they must be one of the supported values for your chosen resolution and frame rate. The valid options are even numbers within the range shown.
LTX-2.3 Fast
- 1080p at 24/25 fps: 6, 8, 10, 12, 14, 16, 18, or 20 seconds
- 1080p at 48/50 fps: 6, 8, or 10 seconds
- 1440p and 4K at 24/25/48/50 fps: 6, 8, or 10 seconds
LTX-2.3 Pro
- 1080p, 1440p, and 4K at 24/25/48/50 fps: 6, 8, or 10 seconds
If you need generations longer than 10 seconds, use LTX-2.3 Fast at 1080p with 24 or 25 fps — that combination supports up to 20 seconds. For longer output at higher resolutions, consider chaining generations using the Extend endpoint.
How resolution affects cost
Higher resolutions cost more per second of output. 4K is four times the price of 1080p at the same model tier. For prototyping and iteration, 1080p on LTX-2.3 Fast is the most cost-effective option. See What does the LTX API cost? for current pricing.
Full reference
For the complete resolution and parameter combinations per endpoint, see the Supported Models page in the API docs.