How to generate videos with Wan 2.7

Much longer clips. This is the headline. Where 2.5 caps out around five to eight seconds, 2.7 runs flexibly from about two up to roughly fifteen seconds. Fifteen seconds is long enough to hold a short beginning-middle-end, which is why 2.7 is aimed at finished, watchable content rather than raw motion assets.

Built-in prompt optimization. The model can expand and refine a short prompt for you before generating. This lowers the skill floor (a rough prompt still gives a decent result) but knowing how to write a strong prompt yourself still gives you far more control over the outcome.

Audio carries over from 2.5, and generating it across a much longer clip is a harder problem than a five-second one. Treat it as the same feature under more pressure, not a new one; the prompting advice below and 2.5's audio behavior both apply, whichever tier you're on.

The cost of all this is real. 2.7 is the expensive tier and a heavier model, so each second costs more and takes longer than the same second on 2.5. It earns that cost when length is the point; it wastes it when it isn't.

Treat sound as a described layer, the same way you describe motion. Name the ambient sound of the scene ("waves rolling onto the shore," "a quiet room tone with distant traffic," "wind moving through trees") so the audio matches what's on screen. Mismatched sound is more jarring than no sound at all.

For voice, describe the manner, not a script you need read verbatim: "she is speaking softly," "a calm, warm voice." Keep it simple and let the model fit the voice to the subject and motion. Over-specifying a long line of dialogue in a few seconds is the audio equivalent of asking for too much motion.

Keep audio and action in sync. If the subject's mouth moves, the voice should be present; if a wave breaks on screen, the sound should land with it. When in doubt, describe fewer, simpler sounds that belong to what's visible: a clean, matched soundscape beats a busy, drifting one.

Set expectations honestly: audio quality isn't always reliable. We've had renders where a collision on screen produced a sound that didn't land right, and human vocalizations (moans, grunts, that register) come out flat or off compared to how they should sound for the visible action. Review every clip with sound on before you ship it; the visual can be perfect while the audio quietly isn't.

A five-second clip can run on a single sentence of motion. A fifteen-second clip cannot: left to one instruction, the model runs out of direction and the back half drifts or repeats. The fix is to script the clip as a timeline, giving the action second by second.

Write it as timestamps: a line for each second (or every couple of seconds) describing what is happening at that moment. "At 00:00, she is standing at the window looking out. At 00:03, she turns slowly toward the camera. At 00:06, she smiles and steps forward." Each beat hands off to the next, so the model always knows what comes next and the clip reads as one continuous action instead of a loop that lost its way.

Keep each beat small and physically continuous with the one before it. A person can turn, step, and smile in fifteen seconds; they cannot cross a room and change outfits. The timeline is for pacing and sequence, not for cramming in more than the runtime can hold.

Silent, short assets. If you need loops, animated thumbnails, or quick social clips with no sound and no need for length, 2.2 does it for a fraction of the cost. Paying for 2.7's audio and duration you won't use is pure waste.

High-volume work. When you need many clips and per-clip cost dominates, the cheaper models are the right engine. Reserve 2.7 for the hero pieces where audio and a full fifteen seconds change what the viewer gets.

Fast exploration. Burn through your rough ideas on a light, cheap model, then bring only the winner to 2.7 for the finished, sounded version.

Audio doesn't match the scene: your prompt described sound that isn't on screen, or none at all. Name the specific ambient sound that belongs to the visible action, and keep it simple.

Long clip drifts or repeats in the back half: you gave one instruction for too much runtime. Script it as a second-by-second timeline so every beat has direction.

Costs are ballooning: you're iterating at the premium tier. Move trial-and-error to short, silent, lower-resolution runs and reserve full 2.7 renders for finals.

Optimized prompt changed your intent: the built-in optimizer expanded the prompt in a direction you didn't want. Treat its output as a draft and edit it back toward your goal.