How to create a mp3-clip from an existing mp3? Is there a free audio tool where I can just grab a snippet from a mp3 file and save it as a new mp3?
Open it in QuickTime Player, click Edit → Trim… (⌘T), drag the yellow handles to truncate it to the snippet you want, and export the result.



Note that it will export in AAC (.m4a) format, so if you need MP3, you'll need to convert it afterwards.