Which AI Video Model Should You Use? A Guide by Use Case

The fastest way to pick an AI video model is to stop comparing models and start with the job. "Which is best?" has no answer; "which is best for a 9:16 product ad with a recurring character?" does. This guide works backwards from what you're making to the model that fits — and most of the time, the right call is to use more than one.

Start with the job, not the model

Every model below is strong; none is strong at everything (that's the whole point of our best AI video generator breakdown). So pick by the constraint that matters most for this piece — speed, audio, realism, or consistency — and let that point you to the model.

Social shorts & UGC ads

You need volume and speed: lots of variations, fast, in vertical. Reach for Seedance for quick iteration and native multi-shot, or Kling when you want its one-click effects. Start from a real product image so the item stays exact — see AI ad maker and UGC ads for the full playbook.

Cinematic & narrative film

You need believable motion, sound, and mood. Veo 3.1 is the safe pick for cinematic shots with synced audio, with strong realism and prompt adherence. (Compare Veo and Kling.)

Product videos

The product has to be exactly itself in every frame, so start from a clean product still and animate it (image-to-video). Kling and Seedance are strong here; get the still right first with AI product photography.

A recurring character or a series

Consistency is everything: the same face, outfit, and style across many shots. Kling is the standout for identity preservation across shots — the reason it's a common default for character-driven work. Lock the character first; see how to keep characters consistent.

Stylized or art-directed looks

When the look is the point — a specific grade, a designed aesthetic, video-to-video restyling — Runway Gen-4.5 gives you the most creative control, including Aleph (video-to-video) and Act-Two (performance transfer).

Talking-head & avatar clips

For a presenter or spokesperson, Kling's AI Avatar and Hailuo's expressive image-to-video are the ones to try.

The quick version

Or let the agent decide

The catch with picking per shot is that one project spans several of these jobs — a single ad might need a product shot, a character shot, and a stylized closer. That's a lot of model-switching. So you can also just describe the piece and let Bucksy route each shot to the right model automatically, using every model above behind one chat. You stay the director; it handles the matching. For the full pipeline, see how to make AI videos end to end.

Frequently asked questions

Which AI video model is best for ads? For fast, high-volume social ads, start with Seedance for speed or Kling for effects, working from a real product image. See our AI ad maker guide.

Which model should I use for a consistent character? Kling — it's the standout for keeping a character recognisable across shots.

Do professionals use one model or many? Many. A finished piece typically mixes models — one for the establisher, one for the character, one for B-roll — which is why an all-in-one workspace is the practical setup.

How do I choose without testing each one? Use the table above as a starting point, then run your actual prompt through the top one or two in Bucksy and keep the better take.