If you have ever needed to convert and image, video, or file take a look into Tinywow.com. It is a free website that is very user friendly.
At the top of the page you will see the different items you can convert that then shows all of the different file types you can convert your file to.
I used this with a fellow teacher recently when she needed her pictures she took converted from her iPhone (HEIC) to a JPG.
Embedded below is a 1 minute and 21 second YouTube tutorial.