AAC to FLAC for Podcasts

Podcasters hit this specific conversion because HLS streaming segments is where the AAC came from — a remote guest, a field recording, a clip — and a bare .aac stream lacks the container index that tells software its duration, so players won't list it and editors import it wrong. For a show you need FLAC, so the AAC-to-FLAC step is part of the edit, not an afterthought.

Edit in FLAC, publish in something lossy. Keeping the working file lossless means your cuts, levelling, noise reduction, and EQ all happen on raw samples — and only the final episode export is lossy, applied once to the finished mix.

Podcast bitrates are lower than most people assume, deliberately. 128 kbps stereo is the widely used standard, and 64–96 kbps mono is entirely respectable for pure speech — it roughly halves the download for every listener, which adds up across a back catalogue and matters to anyone on limited mobile data. Reserve 192 kbps and above for shows where music genuinely carries the experience.

Mono is the decision most worth revisiting. If your episode is voices with no meaningful stereo image — which describes most interview and solo shows — mono at 96 kbps is perceptually equivalent to stereo at 192 and half the size. Publishing stereo by default is a habit, not a requirement. And archive the lossless edit: social clips, best-of segments, and fixes should always be cut from that, never from the published file.

The file gets bigger — roughly 4× — because FLAC stores about 5 MB per minute against AAC's 1.2. For a working file that's irrelevant. AAC is lossy, and the detail its encoder discarded is gone permanently — converting to FLAC cannot restore it. What you gain is that nothing you do afterwards costs any further quality.

Most people meet AAC through HLS streaming segments. It is a fine format there; the trouble is that a bare .aac stream lacks the container index that tells software its duration, so players won't list it and editors import it wrong. FLAC is the destination when you need uncompressed, edit-ready audio that every DAW and editor accepts. Budget for roughly 5 MB per minute — about 4× what the AAC took. You're trading disk for a format that tools actually accept. One honest note on this exact pair: AAC is already lossy, so moving to FLAC cannot restore detail the AAC encoder discarded — it hands you an uncompressed container, not better audio, and the value is a loss-free chain from here on.