# Which AI video engine? How Ask picks the engine, length and format

> How Ask sets the engine, length and aspect ratio from one sentence: family names, plan-gated engines, lengths that snap, format words and what it leaves alone.

Published 2026-09-29 · eroq.ai — canonical: https://eroq.ai/blog/which-ai-video-engine-ask-picks


Three settings shape an AI clip before a single frame renders: the engine, the length and the format — and the first two set most of what it costs. When you describe a clip in the Ask bar at the top of [the studio](/studio), Ask reads your sentence against the studio's own catalogue and puts those settings on the [Video tool](/studio/video). Here is how it reads each one, and what it leaves alone. For Ask itself, start at [/ask](/ask).

## The rule behind every setting

Ask only sets what you asked for. Anything you did not say is left as the Video page already has it — the engine included.

Under its reply, a grey line shows what it set, and about a second later the Video page opens with everything filled in:

```text
You ask:    make a clip of a fox running through fresh snow at dawn
Grey line:  Setting up Video with your parameters…
```

No engine, length or format named, so Ask writes the prompt and changes nothing else. The page keeps the engine it is on: the last one you used, or [Seedance 2.0 Mini](/models/seedance-2-0-mini) on a new free account — available on any plan, 45 credits for five seconds.

None of this spends credits. Ask prepares and opens; Generate stays your click, with the usual credit check and plan unlock.

## Naming an engine

Name an engine — "with Kling", "on Veo 3.1" — and it is set. A family name picks one engine of that family; add the variant to get another:

| You say | Ask sets | Plan | For another, add |
| --- | --- | --- | --- |
| "Kling" | [Kling 3.0](/models/kling-3) | Hobby | "Pro" |
| "Veo" | [Veo 3.1](/models/veo-3-1) | Creator | "Fast" or "Lite" |
| "Seedance" | [Seedance 2.0 Mini](/models/seedance-2-0-mini) | any plan | "2.5", "2.0" or "Fast" |
| "Hailuo" | [Hailuo 3](/models/hailuo-3) | Creator | "Max" |
| "Wan" | [Wan 3.0](/models/wan-3) | any plan | — |
| "Sora" | [Sora 2 Pro](/models/sora-2-pro) | Creator | — |
| "Grok" | [Grok Imagine](/models/grok-imagine) | Hobby | — |
| "Runway" | [Runway Gen-4.5](/models/runway-gen-4-5) | Creator | — |

Two more rules complete the picture:

- **No engine named, the page keeps its current engine** — the last one you used, or Seedance 2.0 Mini on a new free account. Ask does not pick one for you.
- **An engine your plan does not include is proposed, not opened.** Instead of the automatic jump you get the button **Open Video →** with the engine's plan badge, and the Video page opens with its Unlock button.

```text
You ask:    make a vertical clip with Kling of a skateboarder at sunset, 10 seconds
Grey line:  Setting up Video · Kling 3.0 · 10 s · 9:16 with your parameters…

You ask:    make a landscape clip on Veo 3.1 of waves breaking on black rocks, 8 seconds
Grey line:  Video · Veo 3.1 · 8 s · 16:9
Button:     Open Video →   (Creator badge)
```

If your plan includes Kling 3.0, the first opens straight away. The second is a proposal, which is what you see when your plan does not include Veo 3.1.

The variant matters to the bill: "Veo" alone is Veo 3.1, the one that needs Creator, so say "Fast" or "Lite" when you want those. "Kling" never means the Pro — the FAQ below has both prices.

## Six engines, side by side

| Engine | What to say | Plan | Clip | Credits |
| --- | --- | --- | --- | --- |
| [Seedance 2.0 Mini](/models/seedance-2-0-mini) | "Seedance" | any plan | 5 s | 45 |
| [Veo 3.1 Lite](/models/veo-3-1-lite) | "Veo 3.1 Lite" | any plan | 8 s | 112 |
| [Kling 3.0](/models/kling-3) | "Kling" | Hobby | 5 s | 170 |
| [Veo 3.1 Fast](/models/veo-3-1-fast) | "Veo 3.1 Fast" | Hobby | 8 s | 216 |
| [Veo 3.1](/models/veo-3-1) | "Veo" or "Veo 3.1" | Creator | 8 s | 848 |
| [Seedance 2.5](/models/seedance-2-5) | "Seedance 2.5" | Creator | 5 s | 310 |

Credits are for one clip of that length. The whole lineup is on [/models](/models), and the plans are on [/pricing](/pricing).

## Length: say the seconds

Say the seconds — "10 s", "a 15-second clip" — and Ask sets them. The grey line repeats the length you asked for; the Video page then snaps it to what the engine renders and what your plan allows. Longer clips unlock with a plan: up to 15 s on Hobby, 20 s on Creator, 30 s on Studio.

```text
You ask:    make a 20-second clip of a night train crossing a desert
Grey line:  Setting up Video · 20 s with your parameters…
```

On Hobby, the page brings that down to a length the engine renders within 15 seconds.

Length is the other half of the price, so say it on purpose: Seedance 2.0 Mini is 45 credits for 5 s and 90 for 10 s; Kling 3.0 is 170 and 340. More in the [clip length guide](/blog/ai-video-clip-length-guide).

## Format: words become aspect ratios

| You say | Ask sets |
| --- | --- |
| vertical, portrait, TikTok, Reels, Stories, Shorts | 9:16 |
| landscape, horizontal, YouTube | 16:9 |
| square | 1:1 |
| cinema, ultra-wide | 21:9 (video only) |

Images take 1:1, 3:4, 4:3, 9:16 and 16:9, so "a vertical image" works and 21:9 stays a video format. Say no format and the page keeps the one it has.

```text
You ask:    make a clip for Reels of rain on a neon street, 10 seconds
Grey line:  Setting up Video · 10 s · 9:16 with your parameters…
```

For a whole vertical workflow, see [vertical clips for TikTok in one sentence](/blog/vertical-ai-clips-for-tiktok-in-one-sentence); the [aspect ratio guide](/blog/ai-video-aspect-ratios-guide) helps you choose the frame.

## Resolution, camera and sound: only when you say so

The other Video settings follow the same rule — set only when you name them:

- **Resolution** — "720p".
- **Camera move** — one of 24, from push-in, tracking and orbit to dolly zoom and FPV.
- **A palette or lighting look.**
- **Takes** — 1 to 4 ("three takes").
- **Sound** — only when you mention it.

```text
You ask:    make three takes of a slow orbit around a vintage car in the rain, 8 seconds, 720p
Grey line:  Setting up Video · 8 s · 720p · ×3 with your parameters…
```

The orbit is set on the page too; the grey line sums up engine, length, format, resolution and takes, not every setting.

## Not sure which engine? Ask first

Ask answers questions from the studio's live catalogue, then offers to open the right tool:

```text
You ask:    what's the cheapest video engine?
You ask:    which engine does 1080p with sound?
```

Because these are questions, the offer comes as a button rather than an automatic jump. Then refine in the same thread — "rather with Kling", "make it 5 seconds", "the same but vertical" — and what you said earlier still counts. [Iterating by conversation](/blog/iterate-ai-video-by-conversation) walks through a full session, and [making a video by describing it](/blog/make-an-ai-video-by-describing-it) starts from the first sentence.

## FAQ

### Which video engine does Ask use if I don't name one?

None — the Video page keeps the engine it is on: the last one you used, or Seedance 2.0 Mini on a new free account (any plan, 45 credits for five seconds). Name an engine when you want a specific one.

### Does "Kling" mean Kling 3.0 or Kling 3.0 Pro?

Kling 3.0, which needs Hobby and costs 170 credits for five seconds. Say "Kling 3.0 Pro" for [the Pro](/models/kling-3-pro), which needs Creator and costs 225 credits for five seconds.

### What happens if I ask for an engine my plan doesn't include?

Ask proposes instead of opening: you get the button Open Video → with the engine's plan badge. Click it and the Video page opens with that engine and its Unlock button. Nothing is charged.

### How long can an AI video clip be?

Say the seconds and the Video page snaps them to what the engine renders and what your plan allows. Longer clips unlock with a plan: up to 15 s on Hobby, 20 s on Creator and 30 s on Studio.

### Can I change the engine after Ask has set it up?

Yes. Follow up with "rather with Kling" and the rest of what you said still counts, or change it on the Video page before you click Generate.

[Describe your next clip in the studio](/studio) — name the engine, the seconds and the format, then read the grey line before the page opens.