Last year, Microsoft announced the availability of Visio Online Preview. Today, they announced January 2017 Updates for Visio Online Preview. In this release, they are adding support for VSD file format and new cloud storage options for storing and viewing Visio diagrams on the web.
Previously, Visio Online Preview users were able to view their .vsdx files on the web, but now they can also view .vsd files right in your browser. VSD file format is the default file open and save format for Visio 2003, 2007 and 2010.
Previously, Visio Online Preview was available only for diagrams that are stored in SharePoint Online and OneDrive for Business. But now, it is supported on Exchange Online and Outlook.com as well. Users can now view attached Visio files directly in the browser.