Kling 3 and Seedance 2 share the same aspect-ratio options and the same 0-to-2 reference-image limit, so the decision between them comes down to two other parameters: resolution floor and audio. Seedance 2 offers a 480p option that Kling 3 doesn’t list, which can be useful for a fast draft pass before committing to a higher resolution. Kling 3’s lowest listed resolution is 720p.
Audio is the sharper difference. Kling 3 exposes an optional audio toggle, off by default, so you can request a clip with or without sound. Seedance 2’s current Vizify parameters don’t include an audio option at all — every clip is silent. That’s specific to this model: Seedance 2.5, a separate model in the same family, does currently support optional audio in Vizify, so don’t assume the two behave the same way.
Duration overlaps closely: Kling 3 starts at 3 seconds and Seedance 2 starts at 4 seconds, and both currently cap at 15 seconds. If your task needs the shortest possible clip or audio flexibility, Kling 3 covers both; if a silent draft at 480p is what you’re after, Seedance 2 is the more direct route.