Audio quality levels & file formats
  • 20 Aug 2023
  • 1 Minute to read
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Audio quality levels & file formats

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  • PDF

Article Summary

All podcast episodes published on our platform are made available as 3 quality profiles to end users.

Different quality levels are employed to enable a better experience for users on slow (or expensive) internet connections while still allowing other users to receive high quality audio.


QualityFormatBitrateSample rateData useConnection type
LowAAC28k32kHz± 13 MB / hour2G+
MediumAAC64k44.1kHz± 29 MB / hour3G+
HighMP3128k44.1kHz± 58 MB / hourADSL/Fibre
  • The low quality profile enables extremely small file sizes, while still providing perfectly fine fidelity for consuming speech-centric content.
  • The medium profile doubles the bitrate and produces a result that will satifisfy the vast majority of listeners.
  • The high profile doubles the bitrate again and mostly benefits users who listen on fast internet connections, in quiet environment using good sound equipment.

File formats

Supporting two different file formats (AAC & MP3) ensures wide platform support. While AAC is almost universally supported at this point, our player will intelligently detect when a browser does not support it and use the MP3 version.

AAC is used for the two smaller file-size profiles, because of it's massive improvement over MP3 at these lower bitrates. MP3 is used for the high quality one where the quality differences between AAC and MP3 are much less noticable.

Music content

Our quality profiles are tuned for speech-centric content like podcasts, audiobooks and news broadcasts. Ambient music, intros, outros and other jingles will still sound acceptable on the lower profiles, but only the high quality profile provides a good music listenening experience.