Convert MP3 to text, free

What an MP3 file actually is

MP3 is the format almost everything can play. It throws away audio information the ear is least likely to notice, which keeps files small at the cost of some fidelity — a trade that has almost no effect on transcription accuracy, because speech sits well inside the frequency range MP3 preserves.

What it means for your transcript

Bitrate matters more than the format. A 32 kbps MP3 recorded to save space strips out enough detail that consonants blur, and that does cost you accuracy. Anything at 96 kbps or above transcribes essentially as well as a lossless file.

The usual problem with MP3

Very low-bitrate MP3s from old voice recorders are the main problem case. If the file sounds tinny to you, the model hears the same thing.

Getting better results

• → If you are exporting the MP3 yourself, choose 128 kbps mono rather than 320 kbps stereo — same accuracy, a third of the size.
• → Mono is fine. Speech transcription gains nothing from a stereo file.