You must be logged in to Vimeo to download source files for Public videos. The source file option is not visible to logged-out users for Public videos. Logged-out users can instead download transcoded versions of Public videos in various sizes. For step-by-step instructions, see How to download a video.
Logged-out users can download source file links for Unlisted and Password-protected videos.
If you would like to share a source file with someone who does not have a Vimeo account, you can change the privacy setting to Unlisted or Password. Or, you can send file links to download.