I have a bunch of videos saved under the .mp4 format. Is there

Use ffmpeg. Open notepad, type:

FOR /F "tokens=*" %%G IN ('dir /b *.mp4') DO ffmpeg -i "%%G" "%%~nG.mp3"

save as .bat and run.

>>284270
https://cloudconvert.com/

Not all at once, but saves the trouble of installing tons of programs for each format.

formatfactory is a free video/audio conversion program that can do this. warning: on install it'll add the Ask toolbar, but it's easy to remove afterwards.

VLC mediaplayer can convert files to other files. Lots of tutorials online. Also a good media player.

http://www.pazera-software.com/products/audio-extractor/