Why does my video get cut off when other people view it?
When you share a link to a video, the recipients will be able to stream up to 15 minutes of it on the preview page of the Dropbox website. To view a longer video in its entirety, they'll need to download the file or watch it using one of our mobile apps.
The 15-minute limit only applies to other people. You can stream your own videos in their entirety on the Dropbox website.