Veo 3.1 and Gemini Omni on HFLUX
Two Google video models. Unlike every other engine here, neither lets you pick the length freely — Veo is fixed at 8 seconds, and Gemini Omni takes no length parameter at all. That changes how each one is billed.
At a glance
| Veo 3.1 | Gemini Omni 1.1 | |
|---|---|---|
| Length | Fixed 8 s | Not settable · 3–10 s out |
| Billed | 8 s | Flat 10 s per run |
| Aspect ratio | 16:9 · 9:16 | 16:9 · 9:16 |
| Resolution | 1080p · 720p | 4K · 1080p · 720p · 360p |
| First / end frame | Both | Both (only together) |
| Reference images | — | 6 |
Veo 3.1
100 credits per second at a fixed 8 seconds, so 800 credits a clip. 1080p and 720p carry the same rate, so the choice does not change what you pay.
Why the length is fixed — Google forces 8 seconds for 1080p, 4K and end-frame combinations. When the billing calculation and the actual generation each decide that separately, the two drift apart and someone loses. 8 seconds is the only value valid across every combination, so the branching was removed and the value fixed.
A first frame alone starts the video from that image. Adding an end frame interpolates between the two — this works on Veo 3.1 only, and the length is then locked to 8 seconds.
Images attached to Veo do not reach the model as references — anything not used as a frame is analysed and the description is prepended to the prompt
Gemini Omni 1.1
| Resolution | Per second | Per run (10 s) |
|---|---|---|
| 4K | 69 | 690 |
| 1080p | 35 | 350 |
| 720p | 23 | 230 |
| 360p | 7 | 70 |
1080p and 4K are upscales — Google's documentation says so directly. The native output is 720p and everything above it is an upscale. The interface carries the same note.
Because the length cannot be set, output lands somewhere between 3 and 10 seconds. Billing is pinned to the 10 second upper bound, so a shorter result never costs more than expected.
Six working modes
- Plain — text only
- Reference — up to 6 reference images, each with a role you assign; reference videos are 3 clips · 3 s each · 9 s total
- Video — edit a video you supply
- Edit — continue editing the result you just made
- Extend — append a scene, 10 seconds at a time up to 40
- Draw — sketch a path over a background image and that line guides the camera and subject movement; the drawing itself does not appear in the result
40 seconds is not a length parameter — it is four 10 second pieces joined end to end When you extend a video you upload, that video has to be 10 seconds or less; continuing from a result the model made carries no such limit
How billing works
Video is billed per second. Veo is pinned at 8 seconds and Gemini Omni at 10. There is no monthly subscription, and credits stay valid for one year from the date of purchase. Failed generations are refunded.
Frequently asked questions
Why can't I choose the length on Veo?
Veo 3.1 is fixed at 8 seconds on HFLUX. Google forces 8 seconds for 1080p, 4K and end-frame combinations, and when the billing calculation and the actual generation each decide that separately the two drift apart. 8 seconds is the only value valid across every combination, so it is fixed outright.
What does one Veo clip cost?
100 credits per second at a fixed 8 seconds, so 800 credits per clip. 1080p and 720p carry the same rate, so the choice does not change the price.
Can I give Veo a first and an end frame?
Yes. A first frame alone starts the video from that image; adding an end frame interpolates between the two. End frames work on Veo 3.1 only, and the length is then locked to 8 seconds.
Which aspect ratios does Veo support?
16:9 and 9:16. Veo does not support 1:1, 4:3, 21:9 or other ratios.
How long is a Gemini Omni clip?
Between 3 and 10 seconds, and the length cannot be specified. Billing is a flat 10 seconds per run, which is 230 credits at 720p. Charging at the upper bound means a shorter result never costs more than expected.
Are Gemini Omni's 1080p and 4K real resolutions?
No. Google's own documentation describes 1080p and 4K as upscaled. The native output is 720p and anything above it is an upscale. The interface says the same.
Can Gemini Omni produce more than 10 seconds?
Only by extending. Each extension adds 10 seconds up to a total of 40. It is not a length parameter — each result is fed into the next request, four times over.
What working modes does Gemini Omni have?
Six: plain generation, a reference mode taking up to 6 reference images, a video mode that edits a video you supply, an edit mode that continues from your previous result, an extend mode that appends a scene, and a draw mode where a path drawn over a background image guides the camera and subject movement.