2019-6-28 · VTT file extension. The table below provides useful information about the .vtt file extension. It answers questions such as: What is the .vtt file? What program do I need to open a .vtt file? How can the .vtt file be opened, edited or printed? How can I convert .vtt files to another format? Where can I find the specifications for .vtt? Which MIME-type is associated with the .vtt extension?