# Builder Checklist: Fair-Retest Kling 4.0 and Seedance 2.5 Inside MixVio

Builders comparing MixVio routes need a checklist, not another marketing matrix. Same Kling 4.0 / Seedance 2.5 catalog labels still diverge by control surface and by the credits you actually confirm. This is a fair-retest workflow you can paste into a notes file.

Facts below are MixVio page facts (checked 2026-10-29). Official Kling user guide and ByteDance Seed Seedance 2.5 page are authority links only — product URLs stay on apex `mixvio.ai`.

## Checklist (copy / paste)

```text
[ ] brief locked (subject / action / setting / camera / pass)
[ ] owned stills+clips staged
[ ] Take A: one mode only (Kling keyframes OR reference)
[ ] live estimate logged BEFORE Generate
[ ] short/low-res proof first
[ ] fail note: Kling returns reserved credits
[ ] Take B: same brief; Seedance first/last OR pack
[ ] exact reservation logged BEFORE Generate
[ ] fail note: Seedance failed runs cost no credits
[ ] raise length/res only after a pass
```

Start from [MixVio](https://mixvio.ai/?utm_source=hashnode&utm_medium=article&utm_campaign=same-model-fair-test&utm_content=smft-hashnode-intro) so both routes share one balance. Prefill OK; nothing runs until Generate. Free and paid plans both work when the balance covers the quote.

![Control surfaces side by side](https://cdn.hashnode.com/uploads/covers/6ac7155f8cadc38d9e483af7/d7e80ede-ffb8-45d4-a8b1-b1d9dce5c891.png)

## Take A helper — Kling

Walk the [Kling checklist](https://mixvio.ai/models/kling-4?utm_source=hashnode&utm_medium=article&utm_campaign=same-model-fair-test&utm_content=smft-hashnode-inline-kling#effect-workspace):

- Duration **3–30s** (whole seconds); res **720p / 1080p**
- Default chip **16:9 · 5s · 720p** = **50** (was 55); range **30–536**
- Native stereo always on (no toggle / no separate audio line)
- Modes: keyframes ≤10 (`@StartFrame` / `@Middle1` / `@EndFrame`) **or** reference ≤15 (`@Image1` / `@Video1`)
- Photos don’t change quote; reference-video seconds do
- No 4K / HDR / Flash / 2-min extend / editing on MixVio

Confirm live estimate → Generate. Failures **return reserved credits**. See [Kling 4.0 user guide](https://kling.ai/quickstart/kling-4-model-user-guide).

![Fair-retest motion](https://cdn.hashnode.com/uploads/covers/6ac7155f8cadc38d9e483af7/f61a57a6-c8b6-4e6a-8ea0-dbabaaa5723a.gif)

## Take B helper — Seedance

Reuse the **same brief** on Seedance 2.5:

- Duration **4–30s**; res **480p / 720p / 1080p**
- Default **Auto · 4s · 480p · Audio On**; page example **38**; range **38–1320**
- Audio on/off does not change quote; length never auto-lengthens without confirm
- Modes: first+optional last **or** pack ≤50 (`@ImageN` / `@VideoN` / `@AudioN`)
- No 4K / separate extend / timeline editor / multi-round on MixVio

Confirm exact reservation → Generate. Failures **cost no credits**. Background: [Seedance 2.5](https://seed.bytedance.com/en/seedance2_5).

## Pseudo log shape

```js
// keep one object per take — not a MixVio API
const take = {
  route: "kling-4" | "seedance-2-5",
  mode: "keyframes" | "reference" | "first_last" | "pack",
  length_s: 5,
  res: "720p",
  live_quote: 50, // number you confirmed
  pass: false,
  fail_credit: "returned" | "not_charged" | null,
};
```

## Bottom line

Same catalog name ≠ same bill. One mode per job, live quote as cost-to-pass, short proof first, failed-take wording logged. When Take A is scored, [Confirm on Seedance](https://mixvio.ai/models/seedance-2-5?utm_source=hashnode&utm_medium=article&utm_campaign=same-model-fair-test&utm_content=smft-hashnode-cta#effect-workspace) with the identical brief. Product links above are apex `mixvio.ai` only — no Hashnode subdomain product URLs.