MP4 to MP3 Converter
Pull the audio track out of any video and save it as MP3 — or M4A, WAV, FLAC and OGG. The decoding and encoding happen inside this tab, so nothing is uploaded and there is no server-side size cap.
How to convert MP4 to MP3
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Add the video Drag it onto the box above or click to pick a file. Your browser reads it from disk — there is no upload step.
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Choose the audio format MP3 for maximum compatibility, M4A for the best quality per megabyte, WAV or FLAC if you plan to edit the audio afterwards.
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Extract and download Only the audio track is written to the new file. Optionally set a start and end time to keep just one section.
Which format should you pick?
Extracting audio from a video always involves re-encoding unless the source audio is already in the target codec. Picking a lossless target avoids stacking a second lossy generation on top of the first.
| Output | Best for | Approx. size per minute |
|---|---|---|
| MP3 | Anything that needs to play everywhere — car stereos, old players, podcasts | ~1.4 MB |
| M4A (AAC) | Best quality-to-size ratio; Apple ecosystem | ~1.0 MB |
| WAV | Editing, mixing, maximum fidelity | ~10.6 MB |
| FLAC | Lossless archive that is still smaller than WAV | ~5–6 MB |
| OGG (Opus) | Smallest file at a given quality, web playback | ~0.7 MB |
Sizes are rough estimates for 44.1 kHz stereo at medium quality. Actual output depends on the source material and the quality setting you choose.
Why the file never leaves your computer
The page loads a media engine into your browser and uses the native WebCodecs API to decode the video's audio track, then re-encodes it into the container you picked. Where the browser has no built-in encoder — MP3 and FLAC, in most browsers — a small WebAssembly build (LAME for MP3, libFLAC for FLAC) is loaded on demand.
That architecture has a few consequences worth knowing about. There is no upload, so the conversion time does not depend on your connection speed. There is no server quota, so a 2 GB file is fine on a machine with enough RAM. And because the engine is cached, the second conversion works even offline.
The trade-off is memory: the whole output file is assembled in RAM before the download starts. On a phone or a machine with 8 GB of RAM, files above roughly 1 GB can fail. If that happens, trim the video first and convert it in parts.
Frequently asked questions
Is there a file size limit?
Not from us — nothing is uploaded. The real limit is your device's memory, because the finished file is assembled in RAM. Up to about 1 GB is usually fine on a desktop; very large files may fail on phones and low-memory laptops.
Does converting to MP3 reduce quality?
Yes, if the source audio was already lossy. MP3 is a lossy codec, so you lose a little information twice: once when the original was compressed, and again here. If the audio matters, export to WAV or FLAC instead — those are lossless, so only the source's quality is preserved, nothing more is thrown away.
Can I convert only part of the video?
Yes. Set a start and end time in seconds before you hit convert. Note that trimming forces a re-encode of the audio, which is slightly slower than a straight extraction.
What if my video has no sound?
The tool will tell you the file has no audio track. There is nothing to extract — silent videos, screen recordings with the mic muted, and some animation exports are like this.
Does it work on iPhone and iPad?
On Safari 16.4 or newer, yes. The MP3 encoder runs in WebAssembly so it works on iOS, but very long files may hit memory limits sooner than on a desktop.
Can I use the result commercially?
The tool adds no watermark, no audio tag and no licensing restriction of its own. Whether you may use the audio depends on the rights you have to the original video — that is between you and the copyright holder.
Do you keep a copy of my file?
No. There is no upload path in the code. You can verify it yourself: open DevTools, switch to the Network tab, and convert something — you will not see a request carrying the file.