When FLAC makes the most sense
FLAC is lossless: it shrinks audio without changing it. The biggest benefit comes when the source sound is uncompressed, and that is common with MOV. Many cameras record MOV with linear PCM audio at 48 kHz and 16 or 24 bits. Converting MOV to FLAC keeps every one of those samples while the file becomes roughly 40 to 60 percent smaller than the same audio as WAV.
Typical cases:
- archiving the sound of interviews, oral history projects or family recordings filmed on a camera;
- keeping a high-quality copy of a live performance recorded with a good external microphone;
- sending clean audio to a sound editor without huge WAV transfers.
iPhone videos are different
iPhones record AAC, which is already compressed with some loss. A FLAC made from it preserves the decoded sound perfectly but is several times larger than the AAC inside the video, and it does not sound better. For iPhone clips, MOV to M4A is usually the smarter choice: it copies the original AAC exactly. Pick FLAC for iPhone sound only when your editing or archive workflow requires it.
Compression levels
The level controls how hard the encoder works. A higher level gives a slightly smaller file and takes a little longer to save. Playback is equally easy at every level, and the sound is always identical. For large archives, a high level saves real disk space over time.
Organizing an archive
- Fill in title, artist and album in Trim & tags. A pattern such as the person's name as artist and the project as album keeps a collection easy to search.
- Use a frame from the video as cover so you can recognize recordings at a glance.
- FLAC plays in VLC, foobar2000, Windows Media Player on Windows 10 and 11, Android, Plex and Kodi. Apple Music does not import FLAC; for a Mac library, use MOV to AIFF instead.
Everything is processed in your browser, and no footage is uploaded. If an editor needs plain uncompressed audio, see MOV to WAV.