"Convert MP3 to text" sounds like a file conversion, like turning a PNG into a JPG. It is not. Nothing in the MP3 format contains text — the words have to be recognised from the sound, which is why the result depends on the recording rather than on the file extension.
That said, the practical steps are simple.
The short version
- Upload the MP3 to a transcription service.
- Choose the output language, or leave it on automatic detection.
- Wait — a one-hour file takes a few minutes, not an hour.
- Read through and fix names and technical terms.
- Copy the text or download it.
Which formats actually work
You rarely need to convert anything first. SpeakToWords accepts MP3, WAV, M4A, AAC, OGG, OPUS, FLAC, WMA, AIFF and WEBM audio, plus MP4, M4V, MOV and 3GP video containers — the audio track is transcribed and the picture is ignored. Voice memos from phones (3GP and AMR on Android, CAF on iPhone) upload directly too.
If your file is something exotic, converting it to WAV or MP3 first with any free converter is enough. Do not convert a low-bitrate file to a higher bitrate hoping to improve it; that adds file size, not information.
File size and length
The upload limit is 500 MB per file, which at typical speech bitrates is many hours. The more relevant limit is the per-plan recording length: 30 minutes per file on the free tier, 2 hours on Basic, 10 hours on Pro.
If a recording is longer than your plan allows, split it. Any audio editor will do it, and splitting on a natural pause — a break in the meeting, the end of a question — keeps sentences intact across the seam.
What actually improves accuracy
In rough order of impact:
- Distance from the microphone. Halving it does more than any software setting.
- Background noise. Constant hum is manageable; other people talking is not.
- Overlapping speech. When two people talk at once, some of it is simply not recoverable.
- Bitrate. Matters least. Anything from 96 kbps upward is fine for speech; below 64 kbps you start losing consonants.
A word about "free MP3 to text" tools
Browser tools that promise unlimited free conversion usually do one of three things: cap you at a few minutes, truncate or watermark the output, or process your audio on a server under terms that let them keep it. If the recording is a client call, a medical appointment or an interview with a source, read what happens to the file before you upload it.
On SpeakToWords the free tier is 15 minutes per month with no card required, files are processed for your account only, and they are deleted automatically.
Try it with one file
Create a free account and upload the MP3 you were going to type out by hand. If it works on that one it will work on the rest — and if it does not, you have lost five minutes rather than an afternoon.
For longer recordings with several people in the room, the notes in transcribing an interview will save you a second pass.