FLAC to MP3
Drag the FLAC file, tap Shift and drop it on MP3. PlanetOS creates an MP3 at the bit rate you set, which takes a fraction of the space and plays everywhere.
How to convert FLAC to MP3
- 1
Start dragging the FLAC file, from the desktop or any folder.
- 2
While you're still holding it, tap Shift. A ring of planets opens around the file, one for each format it can become.
- 3
Drop the file on the MP3 planet. The MP3 copy appears next to the original a moment later.

Keep the FLACs
FLAC is lossless, so it's the right format to archive music in. Convert copies to MP3 for the phone, the car or a player that doesn't read FLAC, and keep the originals.
For the best MP3 quality, choose 320 kbps in Settings → Formats. Apple devices also play M4A, which sounds slightly better than MP3 at the same size.
PlanetOS does all of this on your computer. Your files are never uploaded, and it works without an internet connection.
Questions
Can I convert a whole album folder?
Yes, with Pro. Select all the tracks and drop them at once.
Are tags like artist and album kept?
PlanetOS writes the audio; check your music app if you rely on embedded tags.