Convert MP4 to MP3 - Extract Audio from Video
Upload an MP4 and get back just its soundtrack as an MP3 encoded at a constant 192 kbps. One important limit: if the video carries two or more audio tracks (dual-language films, for example), the MP3 encode fails, so read the FAQ below before you upload.
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What MP4 to MP3 actually does
An MP4 is a container: it usually holds a video stream and an audio stream side by side (some MP4s have no audio at all), plus timing data that ties them together. Renaming a .mp4 to .mp3 will not make a music player read it, and a lecture or concert clip takes up far more space than the sound you want from it. Car stereos, older MP3 players, voice-note apps and most podcast players want a plain audio file, and MP3 is the format all of them read.
On our servers, ffmpeg opens your MP4, discards the picture, selects the audio with -vn -map 0:a?, and re-encodes it with the LAME encoder at a constant 192 kbps. Before that runs, an ffprobe pass checks that an audio stream exists at all, so a silent screen recording is refused with a plain message instead of producing an empty file. Nothing is installed and nothing happens on your device: the file is uploaded, converted in a worker queue, and offered back as a download.
The MP3 is a new encode, not a copy of the AAC track that was inside the MP4, so it is a second lossy generation; speech and ordinary music hold up well at 192 kbps, while a very high-bitrate studio soundtrack loses a little detail. Full length and the original base file name are kept. The video and any subtitle track are not part of the output, and our audio extraction maps every audio stream in the file, so a source with two or more audio tracks fails instead of picking one; there is also no setting for bitrate, sample rate, trimming or start and end points on this page.
People who use this pair usually want one thing: the talk from a recorded lecture, the song from a music video, a podcast episode that was published as video, an interview they need to type up, or a sermon or webinar to listen to on a phone. This page is set up for MP4, and other video containers (MOV, MKV, AVI, WebM, FLV, WMV, 3GP, MPEG) are accepted here as well because they can all be converted to MP3; only audio files are refused, as a tool mismatch.
How to extract MP3 from an MP4
- Confirm the video has sound, and that it has only one soundtrack. Downloaded films and Blu-ray rips often carry several language or commentary tracks, and our MP3 encoder currently fails on those.
- Check the size: up to 50 MB without an account, 100 MB on a free account, 200 MB on Plus, 1 GB on Pro. If your video arrived split into parts (something like movie_Part-1.mp4), join the parts first, because a half file will not decode.
- Open the MP4 to MP3 page and drop in up to 10 files at once (25 on Plus, 50 on Pro). The target stays locked to MP3.
- Start the conversion. Short clips typically finish within a few seconds; a two-hour HD recording takes longer, because the whole file still has to be read.
- Download each MP3. It keeps the original base name with the new extension, and the link stays live for about four hours.
What you get
- Constant 192 kbps MP3 from the LAME encoder, so the bitrate does not fluctuate between quiet and loud passages
- The video stream is dropped entirely, which is why the MP3 is a small fraction of the MP4's size
- Files with no audio stream are detected before encoding and reported clearly instead of producing a broken download
- Audio-only MP4 files (an .mp4 that contains just a soundtrack) convert fine
- Batch upload: 10 MP4s per request as a guest or free account, 25 on Plus, 50 on Pro, with a fair-use cap of 10 jobs per hour per IP
- Download names match your originals, and signed-in users can request an email when a long job is done
Video Tutorial
Watch this step-by-step tutorial to learn how to convert MP4 files to MP3 format online for free using MiConvert.com. No software installation required.
Frequently asked questions
What bitrate is the MP3, and can I choose 320 kbps?
Every MP3 from this page is encoded at a constant 192 kbps; there is no bitrate, sample rate or VBR selector. The MP4 to WAV and MP4 to FLAC pages write lossless files, but they only wrap a soundtrack that was already lossy, so they add size without adding quality.
Is the MP3 the same quality as the audio in my video?
Close, but not identical. The audio inside an MP4 is normally AAC, and we decode it and re-encode it as MP3, so there is one extra generation of lossy compression. We cannot copy an AAC track into an MP3 file, because they are different codecs.
The conversion failed and my video has English and another language. Why?
That is a real limitation on our side. Our extraction maps every audio stream, and an MP3 file cannot hold more than one, so sources with two or more audio tracks fail. Either use the MP4 to OGG page, which does write multiple streams, or remove the extra tracks in MKVToolNix or VLC first.
I get "This MP4 video has no audio track". What now?
The file genuinely contains no sound, which is common with silent screen recordings, timelapses and clips exported muted. There is nothing to extract, so check that the source plays with sound in a player before uploading.
Can I paste a YouTube or social media link?
No. This page converts files you upload from your device, and there is no field for a URL. If the video is online, download it to your computer or phone first, then upload the MP4 here.
Can I extract only part of the video, like one song from a long recording?
Not on this page: the whole soundtrack is converted, with no start and end inputs. Trim the video with our Trim tool first, then run the trimmed file through MP4 to MP3.
The job failed with "Invalid data found when processing input".
ffmpeg could not read the container. Usual causes are a partial download, a file split into parts, or a recording interrupted before the MP4 index was written (you may see "moov atom not found"). Re-download or re-export the video. Note that .m4v files are refused on converter pages.
What happens to my video and my MP3 afterwards?
The conversion runs on our servers, not in your browser, over HTTPS. Your uploaded MP4 is deleted as soon as the job's final attempt ends, and the MP3 can be downloaded for about four hours before it is deleted automatically. We do log file names, sizes, formats and outcomes for diagnostics, and signed-in accounts keep a conversion history row, so do not treat the download link as private: anyone holding it can use it until it expires.