Supported Formats
Digital service providers accept various audio formats. The recommended format depends on the platform:
- WAV (PCM) — Industry standard, uncompressed, 16-bit or 24-bit.
- FLAC — Lossless compression, smaller files than WAV.
- ALAC — Apple Lossless, used by Apple Music.
- MP3 — 320 kbps CBR minimum for distribution.
- AAC — 256 kbps minimum, preferred by Apple.
- OGG Vorbis — Used by Spotify for streaming.
Quality Standards
- Sample Rate: 44,100 Hz (CD quality) — never use 48,000 Hz unless specifically requested.
- Bit Depth: 16-bit for standard distribution, 24-bit for hi-res.
- Bitrate: 320 kbps for lossy formats (MP3, AAC).
- Channels: Stereo (2 channels) — mono only for specific use cases.
- No clipping, distortion or digital artifacts.
Loudness & Levels
Modern streaming platforms normalize loudness using loudness normalization. Target levels:
- Spotify — -14 LUFS integrated, -1 dBTP true peak.
- Apple Music — -16 LUFS integrated (Sound Check enabled).
- YouTube — -14 LUFS integrated.
- Amazon Music — -14 LUFS integrated.
Avoid over-compression. Masters that are too loud will be turned down by platforms, potentially sounding worse than a properly mastered track.
File Naming
Use clear, consistent file naming conventions:
- TrackNumber_Title.wav (e.g., 01_Hello.wav)
- Avoid special characters in file names.
- Include the ISRC in file metadata, not the file name.
Common Rejection Reasons
- Audio quality below minimum standards.
- Clipping or audible distortion.
- Wrong sample rate or bit depth.
- Silence at the beginning or end of tracks.
- Metadata mismatch between audio and provided information.
Mastering Tips
- Use the Audio Analyzer tool to check loudness, peak levels and quality before submission.
- Target -14 LUFS for most platforms.
- Use a true peak limiter to prevent inter-sample clipping.
- Leave 0.5-1 second of silence at the start, 1-2 seconds at the end.
Related Resources