Extracting audio from a video with VLC

VLC really does convert, and its defaults really do produce broken files. Here is the path that works and the three traps on it.

VLC converts video to audio, it is free, and it is probably already on your machine. It also produces a 4 KB file, or a silent one, or one that never finishes, more often than any other tool people try — and always for one of three reasons.

The path that works

1. Open VLC. Do not open the video first — go straight to Media → Convert / Save… (on macOS: File → Convert / Stream…).
2. Add… and choose your video. Then click Convert / Save.
3. In Profile, pick Audio – MP3. This is the step everything hinges on: the default profile in that list is a video profile, and picking it is how people end up with a file that has no sound in it.
4. Click the spanner icon next to the profile to check it: the Audio codec tab should say MP3, the bitrate should be 192 kbps or whatever you want, and — importantly — the Video codec tab's "Video" checkbox should be off.
5. Set the Destination file, and type the extension yourself: output.mp3. VLC does not add one.
6. Start. The progress bar is VLC's normal playback bar; when it reaches the end, the file is done.

The three traps

1. A 4 KB file. The profile's container and codec do not match, so VLC writes a header and nothing else. Almost always this is a video profile selected for an audio-only job, or the Video checkbox left on inside an audio profile. Re-check step 4.

2. No extension. If you type output in the destination box, VLC writes a file called "output" with no extension, and Windows and macOS then have no idea what it is. Type the .mp3 yourself.

3. It looks stuck. VLC converts at playback speed in some builds, so an hour-long video takes an hour. It is not frozen; it is decoding in real time. This is the single biggest reason to use something else for long files.

Choosing between several soundtracks in VLC

VLC uses whichever audio track is currently selected for playback. So for a film with an original and a dub, open the video normally first, pick the track you want under Audio → Audio Track, and only then start the Convert dialog. It is unintuitive and it is the only way to do it in the interface.

By contrast, the extractor here lists every soundtrack with its language and codec and lets you choose before it starts, which is less to remember.

What VLC does to the audio

VLC's audio profiles re-encode. There is no "copy the stream" option in the graphical Convert dialog, so even when the video already contains MP3 audio — most old AVIs do — VLC decodes it and encodes it again, losing a generation for nothing.

If keeping the original audio matters, the alternatives are FFmpeg's -c:a copy or this site, which picks the copy automatically whenever the format allows it and tells you when it cannot. Why that difference matters.

When VLC is still the right answer

• Damaged or unusual files. VLC is famously tolerant of broken indexes and truncated downloads that stricter tools refuse.
• Formats nothing else opens. Old RealMedia, obscure camera containers, DVD structures.
• You are offline on a machine you cannot install anything on. If it is already there, it works.

For everything else — a normal MP4, MOV, MKV or WebM — a browser tab is faster, keeps the original audio, and does not require remembering which checkbox is in which tab of which dialog.