The technology behind Wan 2.5
How the model works, based on public documentation and sourced evidence.
Wan 2.5 is the preview generation of Alibaba's Wan video model family, announced in September 2025. Alibaba describes it as a natively multimodal architecture: instead of a video model with audio bolted on afterwards, a single unified framework is trained jointly on text, image, video, and audio data. Coverage of the launch also notes the team used reinforcement learning from human feedback to improve instruction following and keep sound and picture tightly aligned.
In practical terms, Wan 2.5 generates clips of 5 or 10 seconds at 480p, 720p or 1080p from either a text prompt or a starting image. Because audio is generated in the same pass as the video, dialogue, ambient sound and background music land on the frames they belong to. The model can also follow an uploaded soundtrack and time the picture to it.
The headline change over earlier Wan releases is that native synchronized audio and 1080p output are built in, where previous versions produced silent video that creators had to score and lip sync in post. Alibaba positions this as the fix for the out-of-sync problem common in AI video, with lip movement, sound effects, and music generated to match on-screen motion.
One caveat for anyone coming from the open-source side: Wan 2.1 and 2.2 shipped open weights under the Apache 2.0 license, but Wan 2.5 launched as an API-only preview rather than an open-weights release. As of late 2025 no model weights had been released, and a community request for them on the official Wan GitHub repository remained unanswered.
On Vidney, Wan 2.5 runs text to video and image to video in 5 or 10 second clips at 480p, 720p or 1080p, and every clip comes back with sound; there is no switch to turn it off. Text to video takes 16:9, 9:16 and 1:1 at every size, and 4:3 or 3:4 at 720p and 1080p only, because the 480p tier has no size in those shapes. Image to video keeps the shape of the picture you give it. A five second 480p clip is the cheapest Wan text to video on the site; from 720p up, Wan 2.6 and 2.7 cost less. Uploading your own soundtrack and Wan 2.5's image models are not offered here.