Mixer AI
Kling 4.0 Flash vs HappyHorse 1.1: specs and price
Kling 4.0 Flash — maximum duration: 20 s; input videos: up to 5. HappyHorse 1.1 — resolutions: 720p / 1080p; input photos: up to 9.
When to choose Kling 4.0 Flash and when HappyHorse 1.1
Kling 4.0 Flash
- Maximum duration: 20 s vs 15 s for HappyHorse 1.1
- Input videos: up to 5 vs No for HappyHorse 1.1
- Prompt limit: 8,000 characters vs 5,000 characters for HappyHorse 1.1
HappyHorse 1.1
- Resolutions: 720p / 1080p vs 720p for Kling 4.0 Flash
- Input photos: up to 9 vs up to 7 for Kling 4.0 Flash
- Aspect ratios: 9 vs 5 for Kling 4.0 Flash
Key differences
Specifications
| Spec | Kling 4.0 Flash | HappyHorse 1.1 |
|---|---|---|
| Generation modes | from text / from first frame / from references | from text / from first frame / from references |
| First frame | Yes | Yes |
| Input photos | up to 7 | up to 9 |
| Input videos | up to 5 | No |
| Output audio | — | Native |
| Minimum duration | 3 s | 3 s |
| Maximum duration | 20 s | 15 s |
| Resolutions | 720p | 720p / 1080p |
| Aspect ratios | 9:16 / 16:9 / 1:1 / auto / 21:9 | 9:16 / 16:9 / 1:1 / 4:3 / 3:4 / 4:5 / 5:4 / 9:21 / 21:9 |
| Prompt limit | 8,000 characters | 5,000 characters |
| Price, 1 s · 720p | — coins | — coins |
Price at the same settings
What to compare visually
For a fair A/B test, use the same scene and, where both modes allow it, the same first frame. Inspect motion continuity, character and object consistency, physics and contacts, camera behavior, temporal deformation, in-clip cuts and audio synchronization.
What to inspect with Kling 4.0 Flash
A lighter Kling 4.0: clips of 3–20 seconds in 720p from text and references, or from a start frame.
- Text and references: a prompt up to 8000 characters, up to 7 photos and up to 5 videos totaling up to 20 seconds; the Video sound switch keeps the sound of reference videos.
- Start frame: one optional photo; without it choose 16:9, 9:16, 1:1 or 21:9, with it the format follows the photo.
- Flash gives 720p and up to 20 seconds only; choose Kling 4.0 for 1080p and 30 seconds.
- Start frame mode accepts no video: videos belong to references mode only.
What to inspect with HappyHorse 1.1
A short scene with sound, from text, a starting image or a set of photos.
- Text, one image or references with up to 9 photos.
- 3–15 seconds at 720p or 1080p, with a choice of aspect ratios.
- More photos do not guarantee preservation of every small detail.
- Inspect hand-object contact and speech synchronization separately.
How to run a fair comparison
- Fix the scene, the first frame (if both models accept one), the duration and the resolution.
- Judge motion, not stills: faces, hands and objects should hold across the whole clip and at cuts.
- If sound matters, listen to it separately: dialogue, effects and lip sync differ between models.
- Price a finished clip, not a second: the per-second rate times your real duration, rounded up once.
Sources
Prices, availability and specifications come from the Mixer AI catalog. This is not an independent test: try both models on the same task before choosing.
What we compare
FAQ
Which is cheaper: Kling 4.0 Flash or HappyHorse 1.1?
Price, 1 s · 720p: the prices of Kling 4.0 Flash and HappyHorse 1.1 are in the comparison table and always match the current tariff. The total depends on your settings: the price of the chosen options is shown in the interface before you run.
How does Kling 4.0 Flash differ from HappyHorse 1.1?
Kling 4.0 Flash — maximum duration: 20 s; input videos: up to 5. HappyHorse 1.1 — resolutions: 720p / 1080p; input photos: up to 9.
How should I compare Kling 4.0 Flash and HappyHorse 1.1 fairly?
Fix the scene, first frame, duration and resolution. Watch the motion across the whole clip and listen to the sound separately. Price the finished clip, not one second.
Are both models available in Mixer AI?
Yes. Both models are in the Mixer AI video catalog; the launch button on the page opens Canvas on a computer and the Studio on a phone. The page exists only for models in the current catalog.
Which model is better?
There is no single winner. First rule out the model that lacks the duration, first or last frame, sound or resolution you need, then compare clips on your own scene. The table highlights only measurable differences.