MP3, based on MPEG-1 Audio Layer III, is the best-known lossy audio format. It reduces data by discarding content that is hard for people to hear, so it is lighter than WAV and easy to play almost anywhere. It is widely used for auditioning and sharing finished audio.
What lossy compression means
Converting to MP3 does not store the original PCM data as it is; it encodes it with less information. Decoding it back to WAV will not give you audio identical to what you started with. This is not a fault, but the mechanism that balances file size against sound quality. Keep the original WAV as your production master.
Bitrate affects size and quality
In general, the higher the MP3 bitrate, the more data is available per second and the larger the file. Choose a value that suits the purpose, but remember that the number alone does not determine how good it sounds. The encoder, the source material, stereo versus mono, and whether the bitrate is variable all affect the result.
When MP3 is a good fit
It is convenient when you want to hand over a file for review without assuming anything about the recipient’s setup, or when you want to save space in storage and transfer. It is not suited to mastering submissions, material you will edit heavily later, or use as the source for further lossy compression.
Differences from WAV, AAC, and FLAC
WAV is the uncompressed reference file that is easy to work with in production, FLAC is lossless compression that returns to the original sound, and AAC is lossy like MP3. None is always better than the others, so decide based on whether you will edit, whether size matters, and what the playback destination supports.
Things to watch when converting
Converting from MP3 to another MP3, to AAC, and so on repeatedly can lose information at each stage. Create each format you need from the original WAV instead. For the practical steps of turning a WAV into an MP3 for sharing, use the WAV to MP3 converter.
