Microsoft does offer an official "portable" version of Visio designed to run from a USB drive without installation. If you are looking for a way to use Visio on the go or without a full local installation, there are three primary official alternatives: Microsoft Support 1. Visio for the Web (Closest Official "Portable" Option)
Therefore, any website, torrent, or file-sharing platform that offers a "Microsoft Visio Portable Download" is distributing an unauthorized, likely pirated copy. Downloading and using such versions carries significant risks. Microsoft Visio Portable Download