Bitrate

In-Depth Explanation

Bitrate is the number of bits of audio data transmitted or stored per second, measured in kilobits per second (kbps) or megabits per second (Mbps). It directly determines the audio quality and file size of a compressed digital audio file. Higher bitrates preserve more detail and dynamic range, while lower bitrates sacrifice fidelity to reduce bandwidth and storage requirements.

How Bitrate Works

When audio is encoded by a codec, the bitrate determines how much data is allocated to each second of audio. For lossy codecs (AAC, MP3, Opus), the bitrate controls how aggressively the codec discards audio information. For lossless codecs (FLAC, ALAC), the bitrate varies dynamically based on the complexity of the audio content.

Lossy Bitrates

Lossy codecs use a fixed or variable bitrate. The bitrate sets the quality ceiling:

• 320 kbps: The maximum for MP3 and Ogg Vorbis. At this rate, most listeners cannot distinguish the compressed file from the original. Spotify Premium streams Ogg Vorbis at 320 kbps.
• 256 kbps: The standard for Apple Music (AAC) and YouTube Music (Opus). AAC at 256 kbps is widely considered transparent for casual listening.
• 128 kbps: The threshold where quality degradation becomes noticeable to trained ears. High frequencies sound dull, transients lose definition, and stereo imaging narrows. Spotify Free streams at 128 kbps on desktop.
• 96 kbps and below: Low quality. Artifacts become audible: pre-echo (a faint ghost of a transient before it actually occurs), warbling in cymbals, and a "swishy" quality in reverb tails.

Variable vs. Constant Bitrate

• CBR (Constant Bitrate): The codec allocates the same number of bits per second regardless of content. Simple sections (silence, sustained notes) waste bandwidth. Complex sections (dense mixes, fast transients) may not get enough. CBR is used for streaming where consistent file sizes matter.
• VBR (Variable Bitrate): The codec allocates more bits to complex passages and fewer to simple ones. VBR produces better quality at the same average bitrate. Apple Music and YouTube use VBR encoding.

Lossless Bitrates

Lossless codecs do not use a fixed bitrate. The bitrate fluctuates based on the audio content:

• FLAC at 16-bit/44.1 kHz: Averages 700 to 1,100 kbps depending on the material. A dense rock mix compresses less than a sparse acoustic recording.
• FLAC at 24-bit/96 kHz: Averages 2,000 to 4,000 kbps. Apple Music's hi-res lossless tier streams ALAC at these rates.
• WAV (uncompressed): 16-bit/44.1 kHz stereo is 1,411 kbps. 24-bit/96 kHz stereo is 4,608 kbps. No compression at all.

Real-World Example

You upload a 24-bit/44.1 kHz WAV master to your distributor. The file has a bitrate of 2,117 kbps (2.1 Mbps). Here is what each streaming platform does with it:

The gap between 128 kbps (Spotify Free) and 320 kbps (Spotify Premium) is audible on any decent playback system. The gap between 320 kbps Ogg Vorbis and 800 kbps FLAC is harder to hear on consumer headphones but obvious on studio monitors.

Why It Matters for Independent Artists

1. Upload at the highest possible bitrate. Deliver 24-bit WAV files (2,000+ kbps) to your distributor. The platform downconverts to its target bitrates. Starting from a high-quality source ensures every compressed version sounds as good as possible.
2. Know what your listeners hear. As of 2026, Spotify Premium streams at up to 320 kbps Ogg Vorbis, with FLAC available for lossless subscribers. Apple Music streams AAC at 256 kbps, with ALAC for lossless. YouTube Music streams Opus at 256 kbps. If most of your audience streams on Spotify Free, they hear 128 kbps. Master accordingly.
3. Do not chase lossless delivery for its own sake. If your audience streams on phones with bundled earbuds, the difference between 320 kbps and FLAC is inaudible. Focus on a clean mix and proper LUFS levels instead.
4. Check your masters at 128 kbps. Before releasing, encode your master to 128 kbps MP3 or AAC. If it sounds good at that bitrate, it will sound good everywhere. If the high frequencies collapse or the low end gets muddy, adjust your EQ and re-check.

Read our guide on mastering for streaming platforms for platform-specific bitrate and loudness targets, and our music distribution services comparison to see which distributors deliver high-bitrate files correctly.

Related Terms

• Codec - The encoding technology that operates at a given bitrate
• Lossless - Formats that use variable bitrates to preserve all audio data
• Sample Rate - Works with bit depth to determine the uncompressed source bitrate
• Bit Depth - Determines dynamic range before codec bitrate reduction
• Mastering - The stage where bitrate compatibility is verified