Audio Formats for Podcasting: Recording to Distribution

Podcast audio passes through three distinct phases, and each phase has different format requirements. Recording demands the highest quality capture possible. Editing requires a lossless working format that preserves full fidelity through cuts, crossfades, and processing. Distribution demands small files in a universally compatible format that sounds good on phone speakers and earbuds.

Getting this wrong in either direction costs you. Recording in MP3 means your raw footage already has compression artifacts — every edit and re-export degrades further. Distributing in WAV means 60-minute episodes at 500+ MB, which hosting platforms won't accept and listeners won't download.

This guide covers the complete format pipeline: what to record in, what to edit in, and what to distribute in — with exact specifications for Apple Podcasts, Spotify, and other platforms.

Recording: WAV at 48 kHz / 24-bit

Record your raw audio in WAV at 48 kHz sample rate, 24-bit depth. Here's why each parameter matters:

• WAV: Uncompressed, no encoding artifacts, universal DAW support. Your raw recording should never be lossy — you can't un-compress audio later. FLAC is an acceptable alternative (same quality, smaller files), but WAV is more universally supported by audio interfaces and portable recorders.
• 48 kHz: The broadcast/video standard. If your podcast ever includes video content (YouTube, clips), having audio at 48 kHz avoids sample rate conversion. 44.1 kHz is fine too — the difference is inaudible for speech — but 48 kHz is the more future-proof choice.
• 24-bit: Gives 144 dB of dynamic range versus 96 dB for 16-bit. This headroom means you can set conservative recording levels (-18 to -12 dBFS) without worrying about noise floor. If a guest suddenly shouts, 24-bit captures it cleanly; 16-bit at the same recording level might clip or produce quantization noise on quiet passages.

File size at these settings: ~16.6 MB per minute, stereo. A 60-minute recording session: ~1 GB. That's a lot, but storage is cheap and your raw recording is irreplaceable.

Do not record in MP3. Even at 320 kbps, MP3 introduces artifacts that compound when you edit, process, and re-export. One lossy encode (at the final export step) is acceptable. Two is not.

Editing: Stay Lossless Throughout

Your DAW or audio editor should work with the same format you recorded in — WAV at 48 kHz / 24-bit. Every cut, crossfade, EQ adjustment, compression, and noise reduction happens in this format. When you export for review or share works-in-progress with co-hosts, use WAV or FLAC.

Key editing considerations:

• Processing in 32-bit float: Most DAWs (Audacity, Reaper, Logic, Pro Tools) process audio internally in 32-bit float regardless of the source format. This gives unlimited headroom for effects processing. The 24-bit precision is maintained; float just prevents clipping during intermediate stages.
• Mono vs stereo for speech: If you're recording with a single microphone, your source is mono. Keep it mono throughout editing. A mono podcast exported as stereo doubles the file size with zero benefit — both channels contain identical audio. Multi-mic setups (two hosts, interviews) can be stereo, but for a single-voice show, mono is correct and halves your file size.
• Don't export and re-import lossy: If you need to send a work-in-progress for review, use FLAC (smaller than WAV, still lossless). Exporting as MP3 and re-importing for further editing introduces a generation of loss.

Distribution: MP3 Is the Standard

For podcast distribution via RSS feeds, MP3 is the universal standard. Not because it's the best codec — it isn't — but because it works in every podcast app, on every device, without exception. Apple Podcasts, Spotify, Google Podcasts, Overcast, Pocket Casts, generic RSS readers — all handle MP3 reliably.

Recommended export settings:

Why CBR over VBR for podcasts: some podcast apps and hosting platforms have issues with VBR MP3s — specifically, duration calculation and seeking can be inaccurate because the file header doesn't contain exact timing information. CBR avoids these edge cases. The quality difference between CBR and VBR at 128+ kbps for speech is negligible.

Why Not AAC for Distribution?

AAC at 96 kbps sounds as good as MP3 at 128 kbps for speech — smaller files at the same quality. Apple Podcasts and Spotify both support AAC. But a non-trivial number of podcast apps, older devices, and RSS feed parsers don't handle AAC correctly. The file size savings (~30%) isn't worth the compatibility risk. Use MP3 for distribution unless you're distributing exclusively through a platform that guarantees AAC support.

Loudness Normalization: -16 LUFS and Why It Matters

Loudness normalization ensures your podcast plays at a consistent volume alongside other podcasts. Without it, listeners constantly adjust their volume knob between shows — a terrible experience.

The standard metric is LUFS (Loudness Units Full Scale), an integrated measurement that accounts for how humans perceive loudness across frequencies. The targets:

• Apple Podcasts: -16 LUFS (their Sound Check feature targets this)
• Spotify: -14 LUFS (they normalize to this for all audio)
• YouTube: -14 LUFS
• General podcast standard: -16 LUFS (most hosting platforms recommend this)

If you master to -16 LUFS, Apple plays it as-is and Spotify boosts it by 2 dB (negligible). If you master to -14 LUFS, Spotify plays it as-is and Apple reduces it by 2 dB. Either target works. -16 LUFS is the safer default because platforms that normalize downward (turning it quieter) never introduce artifacts, while platforms that normalize upward might slightly increase noise floor.

Loudness measurement tools: Youlean Loudness Meter (free plugin), iZotope Insight, NUGEN VisLM. Most DAWs also have built-in loudness meters. Aim for -16 LUFS integrated loudness with peaks no higher than -1 dBTP (true peak, measured with intersample peak detection).

Platform-Specific Requirements

Apple technically accepts FLAC and WAV, but file sizes make this impractical for distribution. The RSS <enclosure> tag includes the file's byte size and MIME type — podcast apps use this to estimate download times. A 500 MB WAV episode will deter listeners on cellular data.

Chapter Markers and ID3 Tags

MP3 supports chapter markers through ID3v2 CHAP frames. Chapters let listeners jump to specific segments — invaluable for long-form podcasts. Apps that support chapters: Apple Podcasts, Overcast, Pocket Casts, Castro.

Chapter metadata includes: start time, end time, title, optional URL, optional image. Tools for adding chapters: Forecast (Mac, free, by Overcast developer Marco Arment), Hindenburg Journalist, chapter marker plugins for various DAWs.

Essential ID3 tags for podcast MP3s:

• Title (TIT2): Episode title
• Artist (TPE1): Podcast name or host name
• Album (TALB): Podcast name
• Year (TDRC): Release year
• Genre (TCON): "Podcast"
• Cover Art (APIC): Episode or show artwork (3000x3000 recommended by Apple, JPEG, under 500 KB)
• Comment (COMM): Episode description / show notes

Common Podcast Audio Mistakes

• Recording in MP3: Your raw recording should always be WAV or FLAC. MP3 artifacts compound with every edit and re-export. Record lossless, encode lossy once at the end.
• Exporting stereo for a single-mic show: A mono podcast in stereo wastes 50% of the file size. Both channels are identical. Export mono.
• No loudness normalization: Your podcast plays alongside others. Without normalization to -16 LUFS, listeners adjust volume constantly. This is the number one reason podcast audio sounds "unprofessional."
• Too high a bitrate for speech: 320 kbps MP3 for a speech podcast is pure waste. Human speech occupies a narrow frequency range. 128 kbps mono captures it perfectly. The extra 192 kbps preserves ultrasonic information that doesn't exist in speech.
• Forgetting metadata: Podcast apps display episode titles, artwork, and descriptions from ID3 tags. Missing tags mean blank fields in the listener's app. Always tag your files.
• VBR encoding: While VBR is superior for music, some podcast apps and hosting platforms mishandle VBR MP3s (wrong duration display, broken seeking). CBR is the safer choice for podcast distribution.

Converting Audio for Podcast Use

Common podcast conversion workflows: extracting audio from video interviews, converting guest recordings from various formats, preparing clips from existing episodes.

Useful conversions: WAV to MP3 (final export) | MP4 to MP3 (extract from video) | M4A to MP3 (convert Apple recordings) | FLAC to MP3 (from lossless masters) | OGG to MP3 (from Discord/Zoom recordings) | Opus to MP3 (from WebRTC recordings)

The podcast audio pipeline is straightforward: capture at maximum quality (WAV 48/24), edit losslessly, encode once to MP3 at the end. The most impactful quality improvements aren't format choices — they're loudness normalization, proper mono export, and complete metadata. Get those right and your podcast sounds professional regardless of whether you're recording on a $50 USB mic or a $500 dynamic.

Need to prepare audio for your podcast? Convert WAV to MP3, extract audio from MP4, or convert M4A to MP3 — free at ChangeThisFile.