Aspect ratios by model: every ratio Playcut accepts
Aspect ratio is the single most common cause of a rejected generation on Playcut. Every model publishes a different list, no two providers agree, and a ratio that works on one model returns a provider 400 on another after credits are already held. This page is the cross-model answer: which ratio works on which model, what to use per platform, and which widely-assumed ratios do not exist anywhere in the catalog.
The aspectRatio field is a string like "16:9". It is accepted by the image tools (generate-image-from-text, generate-image-from-reference) and the video tools (generate-video-from-text, generate-video-from-image, generate-video-from-reference).
Image models
Section titled “Image models”Both Gemini image models — Nano Banana Pro and Nano Banana 2 — accept the same 10 ratios. Grok Imagine accepts a different set of 14, including auto.
| Ratio | Nano Banana Pro | Nano Banana 2 | Grok Imagine (Image) |
|---|---|---|---|
auto | ✗ | ✗ | ✓ |
1:1 | ✓ | ✓ | ✓ |
16:9 | ✓ | ✓ | ✓ |
9:16 | ✓ | ✓ | ✓ |
4:3 | ✓ | ✓ | ✓ |
3:4 | ✓ | ✓ | ✓ |
3:2 | ✓ | ✓ | ✓ |
2:3 | ✓ | ✓ | ✓ |
4:5 | ✓ | ✓ | ✗ |
5:4 | ✓ | ✓ | ✗ |
21:9 | ✓ | ✓ | ✗ |
2:1 | ✗ | ✗ | ✓ |
1:2 | ✗ | ✗ | ✓ |
19.5:9 | ✗ | ✗ | ✓ |
9:19.5 | ✗ | ✗ | ✓ |
20:9 | ✗ | ✗ | ✓ |
9:20 | ✗ | ✗ | ✓ |
Seven ratios work on all three image models: 1:1, 16:9, 9:16, 4:3, 3:4, 3:2, 2:3. Use one of those if you want to switch image models without changing your request.
Per-model image lists
Section titled “Per-model image lists”Nano Banana Pro (gemini-3-pro-image-preview) — 10 ratios:
1:1 · 2:3 · 3:2 · 3:4 · 4:3 · 4:5 · 5:4 · 9:16 · 16:9 · 21:9
Nano Banana 2 (gemini-3.1-flash-image-preview) — 10 ratios, identical to Pro:
1:1 · 2:3 · 3:2 · 3:4 · 4:3 · 4:5 · 5:4 · 9:16 · 16:9 · 21:9
Grok Imagine Image (grok-imagine-image) — 14 values:
auto · 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3 · 2:1 · 1:2 · 19.5:9 · 9:19.5 · 20:9 · 9:20
Video models
Section titled “Video models”Only two ratios — 16:9 and 9:16 — work on every video model in the catalog. Everything else is model-specific.
Google and xAI
Section titled “Google and xAI”| Ratio | Veo 3.1 | Omni Flash | Grok Imagine Video | Grok Imagine Video 1.5 |
|---|---|---|---|---|
16:9 | ✓ | ✓ * | ✓ | ✓ |
9:16 | ✓ | ✓ * | ✓ | ✓ ** |
1:1 | ✗ | ✗ | ✓ | ✓ ** |
4:3 | ✗ | ✗ | ✓ | ✓ ** |
3:4 | ✗ | ✗ | ✓ | ✓ ** |
3:2 | ✗ | ✗ | ✓ | ✓ ** |
2:3 | ✗ | ✗ | ✓ | ✓ ** |
21:9 | ✗ | ✗ | ✗ | ✗ |
* Google documents 16:9 and 9:16 for Omni Flash, but Playcut sends no aspect-ratio parameter to it — the output follows the source image. See the caveats below.
** Inherited from Grok Imagine Video classic and not verified on 1.5. xAI publishes no ratio list for the 1.5 model. Treat anything other than 16:9 on 1.5 as unverified.
ByteDance and Alibaba
Section titled “ByteDance and Alibaba”| Ratio | Seedance 2.0 | HappyHorse 1.1 | Wan 2.7 (reference mode) |
|---|---|---|---|
16:9 | ✓ | ✓ | ✓ |
9:16 | ✓ | ✓ | ✓ |
1:1 | ✓ | ✓ | ✓ |
4:3 | ✓ | ✓ | ✓ |
3:4 | ✓ | ✓ | ✓ |
4:5 | ✗ | ✓ | ✗ |
5:4 | ✗ | ✓ | ✗ |
21:9 | ✓ | ✓ | ✗ |
9:21 | ✗ | ✓ | ✗ |
3:2 | ✗ | ✗ | ✗ |
2:3 | ✗ | ✗ | ✗ |
Wan 2.7’s list applies to reference-to-video only. Its animate (image-to-video) and video-edit modes have no aspect ratio parameter at all.
Per-model video lists
Section titled “Per-model video lists”Veo 3.1 (veo-3.1-generate-preview) — 2 ratios: 16:9 · 9:16. Nothing else. Square, 21:9 and every other value are rejected by Google with INVALID_ARGUMENT. Reference-to-video is 16:9 only on Playcut.
Omni Flash (gemini-omni-flash-preview) — Google documents 16:9 and 9:16. Playcut sends no response_format, so the output follows the input image. The picker shows a locked 16:9, which is a label, not a guarantee — a portrait source image produced a 720×1280 (9:16) output in our bench.
Grok Imagine Video (grok-imagine-video) — 7 ratios: 16:9 (default) · 4:3 · 1:1 · 9:16 · 3:4 · 3:2 · 2:3. There is no auto on the video surface.
Grok Imagine Video 1.5 (grok-imagine-video-1.5-preview) — the same 7 are offered, inherited from classic and unverified against xAI’s 1.5 documentation. 16:9 is the safe choice.
Seedance 2.0 (seedance-2.0) — 6 ratios: 21:9 · 16:9 · 4:3 · 1:1 · 3:4 · 9:16, default 16:9. The provider also has an auto value; Playcut deliberately does not offer it.
HappyHorse 1.1 (happyhorse-1.1) — the provider’s full 9-ratio set, all offered: 16:9 (default) · 9:16 · 1:1 · 4:3 · 3:4 · 4:5 · 5:4 · 21:9 · 9:21 (text-to-video and reference-to-video). Image-to-video and video edit take no ratio parameter — the output matches the source.
Wan 2.7 (wan-2.7) — 5 ratios on reference-to-video: 16:9 (default) · 9:16 · 1:1 · 4:3 · 3:4. Animate and video-edit have no ratio parameter.
Common mistakes
Section titled “Common mistakes”Wide-strip ratios do not exist on any Gemini image model. 8:1, 1:8, 4:1 and 1:4 are widely assumed to work on Nano Banana Pro and Nano Banana 2. They appear nowhere in Google’s image-generation documentation, and an 8:1 request failed with a provider 400 in Playcut production. Both Gemini image models accept exactly the same 10 ratios listed above. The widest ratio available on any Playcut image model is 21:9 (Gemini) or 20:9 (Grok Imagine).
auto is Grok-only, and image-only. grok-imagine-image is the only model in the catalog that accepts auto, where the model picks a ratio to suit the prompt. No Gemini model accepts it, and no video model accepts it — including Grok’s own video models. Seedance 2.0’s provider has an auto value that Playcut does not expose.
Wan 2.7 animate has no aspect ratio parameter at all. The output follows the input frame. Sending aspectRatio on Wan animate or video-edit changes nothing; Playcut’s video-edit endpoint accepts the field and does not forward it. The match to the source is also not pixel-exact — the encoder forces width and height to multiples of 16, so a frame can shift by a few pixels.
HappyHorse 1.1 and Wan 2.7 image-to-video have no ratio. There is no ratio parameter on those modes — the output follows the source frame. The web picker hides the control, and the API rejects an explicit non-default aspectRatio with a 400 rather than silently discarding it.
Veo 3.1 is the strictest model in the catalog. Two ratios, nothing else. 1:1 and 21:9 requests fail upstream. Playcut’s pre-submission guard does not currently check the ratio for Veo text-to-video and animate, so a bad value holds credits, dispatches, and then fails at Google. Credits are refunded when the task fails, but you lose the round trip.
Animate letterboxes rather than crops on Veo 3.1. A source image whose ratio differs from the requested aspect ratio gets black bars baked into the video. Match the source to the target ratio before animating.
Ratios are not portable across models. 3:2 and 2:3 work on all three image models and on both Grok video models, but on no other video model. 21:9 works on both Gemini image models, Seedance 2.0 and HappyHorse 1.1 — and on nothing else. If you plan to A/B two video models on the same prompt, use 16:9 or 9:16.
Which ratio for which platform
Section titled “Which ratio for which platform”| Platform / placement | Ratio | Models that support it |
|---|---|---|
| Instagram Reels, TikTok, YouTube Shorts, Stories | 9:16 | Every image and video model |
| YouTube, landscape web hero, presentations | 16:9 | Every image and video model |
| Instagram / Facebook square feed, avatars, thumbnails | 1:1 | All image models; Grok video, Seedance 2.0, HappyHorse 1.1, Wan 2.7 (reference) |
| Instagram portrait feed, Pinterest-style vertical | 4:5 | Nano Banana Pro, Nano Banana 2 (image); HappyHorse 1.1 (video) |
| Cinematic / ultrawide banner | 21:9 | Nano Banana Pro, Nano Banana 2, Seedance 2.0, HappyHorse 1.1 |
| Photography-native stills | 3:2 / 2:3 | All image models; Grok Imagine Video |
| Modern phone full-bleed screenshots | 19.5:9 / 9:19.5 | Grok Imagine Image only |
Two practical consequences. First, 4:5 portrait video exists on exactly one model — HappyHorse 1.1 (text-to-video and reference-to-video). Everywhere else, generate 9:16 and crop, or use 1:1. Second, 21:9 cinematic video is available only on Seedance 2.0 and HappyHorse 1.1 — Veo 3.1, the flagship, cannot produce it.
Verification status
Section titled “Verification status”Ratios on this page are provider-documented values, verified against provider documentation on 2026-07-21 for Nano Banana Pro, Nano Banana 2, Grok Imagine Image, Veo 3.1, Omni Flash, HappyHorse 1.1 and Wan 2.7. Two entries are weaker and worth stating plainly:
- Grok Imagine Video (classic) — the 7-ratio list comes from a mirrored copy of xAI’s capability documentation, not a live page. xAI’s public model pages publish no ratio table.
- Grok Imagine Video 1.5 — the same 7 ratios are offered by Playcut but have never been verified against 1.5. Only
16:9is safe to assume.
Playcut does not offer any ratio that its provider rejects on any model. Where our list is shorter than the provider’s — auto on Seedance 2.0 and Grok Imagine Image — that is a deliberate omission, not an oversight. (HappyHorse’s 4:5, 5:4 and 9:21, previously omitted, are offered since 2026-07-24.)