Unuploaded

Converter · No upload

Video to MP3, without uploading the video

Drop in your own video files — lecture recordings, interviews, phone footage, screen captures — and download just the audio as an MP3: MP4 to MP3, MOV to MP3 and WebM to MP3 all decode reliably in every current browser, because it is your browser doing the decoding. The extraction runs entirely inside your browser: a two-gigabyte video never travels anywhere, and the network meter below proves it live.

Statusidle Files— File— Duration— Sample rate— Channels— Bitrate192 kbps Output size— Network since file read—

How this converter works

When you choose a video from your device, the browser's File API hands this page the bytes in memory — no transfer happens, because the file is already on your machine. Your browser then does the demanding half itself: its built-in media engine reads the container, finds the audio track, and decodes it to raw samples, the same machinery it uses to play video on any web page. Those samples are encoded to MP3 at the bitrate you chose by lamejs, a JavaScript port of the LAME encoder (LGPL), running inside this tab, and the result is handed back as a download link. The video frames are never touched at all — only the sound leaves the container, and nothing leaves your device.

Video is where "no upload" stops being a nicety and becomes arithmetic. An hour of phone footage can be gigabytes; its audio track, a few dozen megabytes; the MP3 you actually wanted, smaller still. Uploading the whole video to a server to get the small part back is the worst possible shape for that job — slow, metered, and a copy of your footage on someone else's machine. Here the big file never moves. The encoder is the one thing that downloads, once, before any file of yours is read, so the meter's zero is honest; the methodology page shows how to verify it and publishes the encoder's license and provenance.

The honest limits: this tool works on your own local video files only — there is no URL box, by design, and the whole track is extracted with no trimming. What your browser can't decode, this page can't read: MP4, MOV, and WebM are dependable everywhere, while MKV and AVI vary by browser and system codecs, and a file with no readable audio gets an error row naming it rather than a silent skip. The output is a re-encode of an already-compressed track, so a small generation loss is unavoidable — 192 kbps (the default) keeps it inaudible for most material. Long videos take real time to decode and encode; the readout shows progress as it runs.

Frequently asked questions

Is my video uploaded anywhere?
No — and for video that's the whole argument. A converter that uploads would need to move your entire file, possibly gigabytes, to its server just to hand you back a few megabytes of audio. Here the browser reads the file from your disk, decodes the audio track in this tab, and encodes the MP3 locally. The readout's network meter counts every request from the moment your file is read and stays at zero, and the methodology page shows how to verify that independently.
Which video files does this work with?
Whatever your browser can decode, because it's the browser doing the decoding. MP4, MOV, and WebM — which covers phone footage, screen recordings, and camera clips — decode reliably in every current browser. MKV and AVI depend on the codecs your browser and system happen to support, so they may or may not work. A file whose audio can't be read gets a clear error row rather than a wrong result.
Can I extract just part of the audio, or does it take the whole track?
The whole track, start to finish — there is no trimming here. The MP3 is exactly as long as the video. If you need a clip rather than the full audio, extract the MP3 first and trim it in any audio editor; cutting a small MP3 is a much lighter job than cutting a video.
How good will the extracted audio sound?
As good as the video's audio track, minus one re-encode. Video sound is usually already compressed (typically AAC), and this tool decodes it and re-encodes to MP3 at the bitrate you choose, so a small generation loss is unavoidable. At the default 192 kbps it's inaudible for most material — and nothing can add quality the recording never had: a phone clip shot in the wind stays a phone clip shot in the wind.
Why did my file produce an error?
The common reasons: the file has no audio track at all (some screen recorders capture silent video), its audio uses a codec your browser can't decode, it's DRM-protected, or it's damaged. The error row names the file so nothing is silently skipped, and the rest of your batch still converts. Trying a different browser genuinely helps for the codec cases — support differs.

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