Unuploaded

Converter · No upload

Convert video to MP3 on your device

Extract the audio from an MP4, MOV or WebM video and download it as an MP3.

Statusidle Files— File— Duration— PCM rate— Channels— Requested bitrate192 kbps Output size— Network since file read—

No audio track, a missing codec, DRM or damage all give the row “no audio track this browser can read”; other extensions are refused as not a video file. Surround is folded to stereo and the row says so; the browser may resample at decode with no note, and peaks over full scale are clipped silently. AVI audio decoding depends on browser support. Takes .mp4, .m4v, .mov, .webm, .mkv, .avi, .ogv and .3gp.

How this converter works

Your browser reads the video into memory, parses its container and decodes one audio track into samples. lamejs, a JavaScript port of the LAME encoder (LGPL), encodes those samples as MP3 at the bitrate you chose, the status shows its progress, and the page offers the result as a download. The MP3 holds only audio.

An hour of phone footage can be gigabytes while its audio track is only a few dozen megabytes, and extracting the audio locally means you do not upload the whole video. The MP3’s size depends on the bitrate you choose, and it can be larger than the compressed audio track it came from. The network meter counts resource-timing entries from the first file read, so it does not include the encoder download that comes before it. The methodology page explains the checks and publishes the encoder’s license and provenance.

This tool works on files from your device and has no URL field. MP4, MOV, WebM, MKV, OGV, 3GP and AVI all depend on the browser's container and audio-codec support; an accepted extension does not mean its audio will decode. Pictures, chapters, subtitles, tags and artwork are not carried across. The PCM rate readout shows the conformed sample-buffer rate sent to the encoder. That is not always the source file's rate, and it is not measured from the finished MP3. A further rate change in the page's MP3-conform step gets a resample note. The bitrate readout and result rows repeat the request, not a measurement of the MP3, and at low PCM rates the encoder can use a lower bitrate. There is no length cap: the whole file and its decoded audio are held in memory, so a large video can fail on a low-memory device.

Frequently asked questions
Is my video uploaded anywhere?
No. The browser reads the video, decodes its audio track and encodes the MP3 in this tab. The methodology page explains how to check the network activity yourself, and what the page’s own meter leaves out.
Which video files does this work with?
MP4 to MP3 works, and so do MOV and WebM, when your browser supports the container and the audio codec inside it. MKV, OGV, 3GP and AVI can vary by browser and system. An accepted extension does not mean its audio will decode. A track the browser cannot read gets a named error row and is not counted as a successful conversion.
Can I extract just part of the audio, or does it take the whole track?
It takes the whole track. The tool extracts the one audio track the browser’s decoder supplies, without trimming, and it cannot pick an alternate language or commentary track. For an excerpt, export the audio first, then trim it in an audio editor.
How good will the extracted audio sound?
No better than the video’s own soundtrack: the output cannot restore detail the source lacks. MP3 encoding is lossy, so when the video’s audio is already compressed, the MP3 adds another generation of loss. Start at the default, 192 kbps, compare the result with the original, and raise the bitrate if you hear a difference.
Why did my file produce an error?
The browser found no audio track it could read. That can mean the video has no audio, uses an audio codec the browser lacks, is DRM-protected or is damaged, and the browser reports all four the same way, so the row cannot say which. The rest of the batch still converts. Another browser may help when the codec is the problem.

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