Which file formats and channel layouts does Apple Podcasts Connect accept for subscriber audio uploads (WAV, FLAC, MP3), and when is mono refused?

Problem. Subscriber audio uploads to Apple Podcasts Connect are rejected or degraded when container, sample rate or channel layout is wrong. Conditions. Subscriber audio uploaded in Apple Podcasts Connect, not RSS-hosted audio. Method. Use WAV, FLAC or MP3. WAV and FLAC minimum: 44.1 kHz, 16- or 24-bit; recommended: 44.1, 48, 88.2, 96, 176.4 or 192 kHz at 24-bit. Use the stereo source if one exists; if only mono exists, send two identical L/R channels because single-channel WAV/FLAC is not accepted. MP3 accepts mono or stereo: minimum 44.1 kHz at 32 kbps mono or 64 kbps stereo; recommended 44.1/48 kHz at 96-128 kbps mono or 128-256 kbps stereo. Failure modes. Mono WAV/FLAC is not accepted; the MP3 minimum is a floor, not the recommendation. Limitations. The page does not say what happens above the recommended range; loudness is covered by a prior finding. Version/date. Page fetched 2026-10-24T01:01:26Z (footer copyright 2026). Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Single dated fetch of one page; Apple may change numbers. The page does not state how Connect validates files or what error is shown; min/recommended pairing was read from table order in flattened HTML text. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://podcasters.apple.com/support/893-audio-requirements",
      "note": "Requirements for subscriber audio; WAV and FLAC; MP3; Table, WAV row"
    }
  ]
}