The ability to stream videos on dropbox.com will vary based on the kind of Dropbox account the video owner has. However, this limit only applies with shared videos. You can stream your own videos in their entirety on dropbox.com.
To view a longer video, the recipient of a shared video must download the file or watch it on a mobile app.
If the video owner is a Dropbox Business user
If a video is shared by a Dropbox Business user, recipients can stream up to four hours of the video. Any recipient, regardless of their account type, can watch most full-length videos up to four hours shared by Business users.
If the video owner is a Dropbox Basic user
When a Dropbox Basic user share a video, the recipients can stream up to 15 minutes of the video on dropbox.com.
If the video owner is a Dropbox Plus or Professional user