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AI Video Aspect Ratio Guide 2026

Which ratio each model actually supports, why generating vertical beats cropping it, and the composition rule that makes one shot work in three formats.

The expensive mistake in AI video is generating 16:9 and cropping to 9:16 afterwards. A crop throws away two thirds of the frame you paid for and relocates your subject off centre, and the models can generate vertical natively at the same price. Choose the ratio before you generate, not after.

TL;DR

Why cropping is the wrong default

You lose most of the image. Going from 16:9 to 9:16 keeps roughly 30 percent of the horizontal frame. Everything you composed at the edges is gone.

The composition moves. A subject placed on a third in 16:9 lands somewhere arbitrary after a centre crop, and the negative space that made the shot work disappears.

Detail drops. Cropping to a tall slice and scaling back up to full vertical resolution means upscaling, which softens exactly the fine detail you chose an expensive model for.

It costs the same either way. This is the part that makes cropping indefensible: generating a native vertical clip is the same credit price as generating the horizontal one. There is no saving to justify the loss.

What each model supports

Ratio support and defaults change with model versions, so treat the selector in the app as authoritative and check before a batch. What is documented:

Gemini Omni Flash: 16:9 default and 9:16, native 360p and 720p with 1080p and 4K upscaled, per Google's Omni model documentation. Audio generated by default. Up to 40 seconds total with extensions, and uploaded video input capped at 10 seconds.

Veo 3.1 (Standard, Fast, Lite): horizontal and vertical both supported. Lite is 720p.

Kling v3, Seedance, Wan, Hailuo H3, Higgsfield Standard: all offer ratio selection including vertical.

The practical rule: the ratio is a setting, not a model choice. Pick the model for the shot and the ratio for the placement.

Cost is identical, so plan by placement

Canon 8frame prices, a credit is $0.01 at pack rate. These are the same whichever ratio you pick:

Model Clip Credits
Wan 3.0 (480p) 5s 24
Veo 3.1 Lite 8s with audio 54
Kling v3 Standard 5s with audio 86
Gemini Omni Flash 8s with audio 135
Seedance 2.5 (720p) 5s 157
Veo 3.1 Standard 8s with audio 448

Which means: if a campaign needs 9:16, 1:1 and 16:9 versions of one idea, generating three native clips on Veo 3.1 Lite costs 162 credits, about $1.62. That is cheaper than most people's instinct and far better than cropping one clip three ways.

Resolution by ratio, and the trap in defaults

Vertical 1080p means 1080 x 1920, which is more pixels than 1920 x 1080 is in the dimension that matters for a phone. Some models price by resolution, and the default is not always the cheap one: Wan 3.0 defaults to 1080p at 95 credits for 5 seconds, against 24 at 480p. Set the resolution deliberately or the model you picked because it was cheap bills four times what you expected.

For vertical social where the clip plays at phone size with motion and grade over it, 480p drafts and 720p finals are usually enough. Reserve 1080p for anything holding still on screen or going to a larger display.

The composition rule for multi-format work

When you genuinely need one shot to survive several ratios, compose for a safe centre:

Prompt for it explicitly: state the subject's placement and ask for uncluttered space where you need it. Then draft at 24 credits on Wan 3.0 at 480p and check the framing before committing to a finished take.

Which ratio for which placement

Placement Ratio
Reels, Shorts, TikTok, Stories 9:16
YouTube main feed, landing page hero 16:9
Feed posts where vertical is cropped in preview 4:5 or 1:1
Pinterest 2:3 stills, per Pinterest's own recommendation
Connected TV and presentations 16:9

For platform-specific duration and file limits, read the platform's current ad or creator specs directly. Those change, and a blog table goes stale.

FAQ

Does vertical video cost more to generate? No. Credit price is set by model, duration, resolution and audio, not by ratio.

Can I generate 4:5 natively? Model-dependent. Where it is not offered, generate 9:16 and crop to 4:5, which loses far less than cropping from 16:9.

Is it better to generate three ratios or crop one? Generate three. At Veo 3.1 Lite prices that is 162 credits for all three, and each one is properly composed.

What resolution should vertical social video be? 720p is enough for most social placements. 1080p when the shot holds still or plays larger.


Pick the ratio first, draft at 480p, then commit. The 8frame canvas is free and unlimited, and generation is paid from $19/month.

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