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Any audio your browser can play, as an MP3
MP3 is the one format every phone, car stereo, editing app and upload form accepts. The files people actually have are often something else: an M4A from the iPhone Voice Memos app, a WAV export from a recorder or a DAW, an AAC or OGG/Opus voice note, or the sound of an MP4 video. This page turns any of them into an MP3.
The conversion runs in your browser. The audio is decoded by the browser’s own decoder — the same one that plays it — and encoded by LAME, the reference MP3 encoder, compiled to run on the page. The file is never uploaded, so an unreleased track, an interview or a voice message stays on your device.
MP4 to MP3: taking the sound out of a video
Drop in an MP4 or MOV and you get its sound track as an MP3 — a lecture to listen to on the way, a song from a clip you filmed, the audio of a screen recording. The picture is simply left behind. A 5.1 film soundtrack is mixed down to stereo by the standard speaker rules, not by dropping channels.
Which bitrate to choose
| Bitrate | Size per minute | Good for |
|---|---|---|
| 128 kbps | about 1 MB | Speech, voice notes, podcasts, upload limits |
| 192 kbps | about 1.4 MB | Music and speech — the default |
| 320 kbps | about 2.4 MB | Music from a lossless source (WAV, FLAC) |
Converting from a file that is already compressed — M4A, AAC, OGG, a video’s sound — loses a little more quality, because MP3 throws away detail again. A higher bitrate cannot bring back what the source no longer has, so 320 kbps only pays off when the source is lossless. If you need an exact copy rather than a smaller file, keep the original.
What the MP3 does not carry over
Decoding keeps only the sound. The new file has no tags at all: no title or artist, but also none of the encoder names, comments, cover art or GPS location an M4A from a phone or an MP4 from a camera can hold. If you only wanted those gone and want to keep the format, the audio metadata remover cleans M4A, MP4, OGG, FLAC and WAV files without converting them.
Limits worth knowing
- What the browser cannot play, it cannot convert. WMA and AMR files do not decode in current browsers. Safari decodes Opus only in recent versions.
- Very long recordings use a lot of memory. The whole recording is decoded at once, about 21 MB per stereo minute, so a file several hours long can exceed what a phone allows. Split it, or use a computer.
- The output is always 44.1 kHz. The CD rate, which every player handles; the browser resamples while decoding.
How to convert a file to MP3
Step 1: Add the file
Drag in an M4A, WAV, AAC, OGG, FLAC, MP4 or MOV file. You can select several and convert them in one batch.
Step 2: Choose a bitrate
192 kbps suits music and speech; 128 kbps keeps voice notes small; 320 kbps is for music from a lossless source.
Step 3: Convert and download
The progress bar follows the encoding. One file downloads as an MP3, several arrive as a ZIP. Your original stays unchanged.
Frequently Asked Questions
Is my file uploaded to a server?
No. Decoding and encoding both happen in your browser; the file never leaves your device. You can disconnect from the network once the page has loaded and the converter still works.
How do I convert MP4 to MP3?
Drop the MP4 into the box above, choose a bitrate and press convert. The video’s sound track comes out as an MP3; the picture is left out.
Can I convert an iPhone voice memo (M4A) to MP3?
Yes. Voice Memos saves M4A files; drop one in and it comes out as an MP3 that any app or form accepts. 128 kbps is plenty for speech and keeps the file small.
Does converting to MP3 reduce quality?
MP3 is a lossy format, so it keeps less than a WAV or FLAC — at 192 kbps most people cannot hear the difference. From a source that is already compressed (M4A, AAC, OGG) a little more is lost on top.
Are the tags kept?
No. The MP3 carries no tags — no title or artist, but also no encoder names, comments, cover art or location from the original. Add a title afterwards in your music app if you need one.
Which formats can it read?
Whatever your browser can play: M4A, AAC, WAV, FLAC, OGG and Opus, MP3, and the sound of MP4, MOV and WebM videos. WMA and AMR do not decode in current browsers.
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