Bitrate
Bitrate is the amount of data used per second of audio, in kilobits per second (kbps) — the main quality dial of lossy formats like MP3, AAC and Opus.
Different codecs spend bits with different efficiency: Opus at 64 kbps rivals MP3 at 128 kbps for speech. For spoken word, 64–96 kbps mono in a modern codec is typically transparent; music pushes higher.
Uncompressed bitrate is fixed by the math: 16-bit stereo at 44.1 kHz is about 1,411 kbps, which is why lossless files are an order of magnitude larger than good lossy ones.
Related terms
Frequently asked
What is Bitrate?
Bitrate is the amount of data used per second of audio, in kilobits per second (kbps) — the main quality dial of lossy formats like MP3, AAC and Opus.
Why does Bitrate matter?
Different codecs spend bits with different efficiency: Opus at 64 kbps rivals MP3 at 128 kbps for speech. For spoken word, 64–96 kbps mono in a modern codec is typically transparent; music pushes higher.
What terms are related to Bitrate?
Closely related concepts: Lossy compression, Codec, Sample rate — each has its own entry in this glossary.