Things generic ChatGPT and Claude get wrong about Seedance

I use AI to help me write Seedance prompts, and both ChatGPT and Claude are confidently wrong about the specifics. Not about how to write a good prompt in general, but about how this model actually behaves.

So I built something to check a prompt against the documentation before running it. You paste in what you were going to use, and it gets checked against Dreamina's own prompt guidelines. That is the whole point of it. It is a lookup step before you spend credits.

A few things it catches, all of which are in the documentation and none of which a generic model got right for me:

• Audio cannot be your only reference. It also does not work with text alone. Audio has to be paired with at least one image or video reference.
• I2V crops from the centre. If your output aspect ratio does not match the aspect ratio of your input image, the model crops to fit, centred, with no black borders. Anything important near the edge is gone.
• Removal edits work better when you state what should stay unchanged. The documentation frames this as a recommendation, not a strict rule — naming what to remove and specifying what stays the same gets a better result. It does not spell out what happens if you leave that out.
• Extending a clip keeps a bit of the original by default. The tail end of the original is usually carried into the output automatically. What prompting adds is control over how much of the original comes through, up to the full clip, not whether any of it survives at all.

None of this is craft advice. It is just how the model works, and you either know it or you waste generations finding out.

It is a skill that plugs into Claude, covering modes, input specs, prompt structure, character consistency and troubleshooting. There is a Custom GPT version for people not on Claude. Both are free.

Seedance 2.5 is rolling out now and the full documentation is not public yet. I have added what we know so far, so both tools work for 2.0 and 2.5, I am updating it as more info about 2.5 comes out.

If you know all of this by heart you do not need it. I do not. Seedance is not the only model I use, and what holds in one model does not hold in another.

If you use Seedance a lot and something in there is wrong, tell me and I will fix it.