MediaChef MP4 to MP3
Convert MP4 to MP3 — free, offline, on your computer
MediaChef ships a recipe called “Extract audio to MP3”. Drop a video on the board, pick a bitrate, press start: the soundtrack is written next to the original as an MP3. The file never leaves your machine, there is no size limit, and the whole thing works with the network off.
Free and open source — read the code on GitHub All files and release notes
How to convert MP4 to MP3
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Download MediaChef
One file for macOS, Windows or Linux. FFmpeg is already inside — nothing to install separately, nothing to add to PATH.
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Drop the MP4 on the board
MediaChef reads the file with ffprobe and keeps only the recipes that suit it. A video with an audio track gets the MP3 card straight away.
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Pick “Extract audio to MP3”
Choose the bitrate: 128k for speech, 192k as the default, 320k for archiving. The command preview updates as you switch.
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Press start and take the file
The MP3 appears next to the video as clip.audio.mp3. The queue shows progress, time left and the finished path.
Which bitrate to pick
The recipe offers three bitrates. Sizes below are for one hour of audio — arithmetic from the bitrate, so a two-hour recording is simply double.
| Bitrate | One hour of audio | Pick it when |
|---|---|---|
128 kbps | ≈ 58 MB | Speech: interviews, podcasts, lectures, voice memos. Smallest file, no audible cost on a voice. |
192 kbps | ≈ 86 MB | The default. Music you actually listen to, and anything you are not sure about. |
320 kbps | ≈ 144 MB | Archiving, or audio you will edit further and re-encode again later. |
Not only MP4: the same recipe shows up for MKV, MOV, WebM, AVI, TS and anything else FFmpeg can read, as long as the file has an audio track.
Why convert on your computer
Nothing is uploaded. A recorded call or an unreleased cut stays on your disk. There is no server copy to trust a retention policy about.
No size cap. Online converters stop at 100 MB to 2 GB and put you in a queue. A four-gigabyte screen recording converts the same way a four-megabyte one does.
Faster on real files. Extracting an existing audio track is quick. Uploading the video first is the slow part — and locally that part does not exist.
Free, with no account. GPL-3.0 open source: no sign-up, no trial, no watermark, no per-file limit.
Batches, not one at a time. Drop every clip on the board at once; the queue works through them and tells you where each MP3 landed.
FAQ
Does converting MP4 to MP3 lose quality?
MP3 is a lossy format, so the track is re-encoded once. At the default 192 kbps that is inaudible on speech and very close to it on music. If the file is a master you will work with further, take 320 kbps.
What is the largest file I can convert?
MediaChef sets no limit — your free disk space is the limit, and the app checks it before starting. Length does not matter either: a three-hour recording is one job in the queue.
Does it work without internet?
Yes, completely. FFmpeg ships inside the download, so conversion never touches the network. Only transcription needs a one-time model download.
Can I convert several videos at once?
Yes. Drop them all on the board, add the recipe, and the queue runs them one after another with progress and time left for each.
Is there a watermark or a paid tier?
No. MediaChef is GPL-3.0 open source with no paid tier at all, and it does not touch your audio beyond the conversion you asked for.
If I change an MP4 to MP3, does the original video stay?
Yes. MediaChef reads the video and writes a new MP3 next to it — the MP4 is never overwritten, renamed or deleted, so you can turn the same file into audio as many times as you like. Nothing is uploaded either: the whole thing runs without internet.
Get the MP3 out of that video
MediaChef 0.8.5 — free, open source, macOS · Windows · Linux.
Free and open source — read the code on GitHub All files and release notes
MediaChef is young: builds are not yet signed by Apple or Microsoft, so the first launch asks for confirmation — a plain-text how-to ships inside every download.
Something broken, or something missing? Write to us: hello@mediachef.app