Video
Keyframe
A keyframe is a frame whose content is fixed rather than generated, and which the motion is built around. In AI video the start frame and, where supported, the end frame are the keyframes.
Fixing a frame converts an open-ended generation into a constrained one. The engine no longer invents the subject, only the journey — which is why a keyframed clip is far more predictable than a text-only one.
Two keyframes turn the clip into a transition between two images you already approve, which is the most reliable way to make a generated shot land exactly where the edit needs it.
On eroq
Every engine accepts a start frame — a photo, a render from the image studio, or a saved Character. The three Seedance engines also accept an end frame and interpolate between the two. The end frame is only read when a start frame is present.
Questions
Which engines take two keyframes?
The Seedance engines — 2.5, 1.0 Pro and 1.0 Lite. Kling, Hailuo, Veo 3 Fast and Motion One take a start frame only.
Can I give only an end frame?
No. The end frame is read only when a start frame is there too, because the engine interpolates between the pair rather than working backwards from one image.
Does a keyframe guarantee the subject stays the same?
It anchors it strongly but does not freeze it — the further the clip travels from the keyframe, the more drift you get, which is one reason shorter clips hold together better.