When you actually need to mute a video
More often than you would think. Maybe a colleague's background conversation got picked up during a screen recording. Maybe a notification chime fired while you were demoing something. Maybe you are repurposing a video for an Instagram reel that is going to play with its own soundtrack on top, or for a Twitter embed that needs to autoplay muted anyway. In all of those cases you do not want to fade the audio or re-encode — you want it gone, the picture untouched, and the file ready to upload again.
What this tool does, exactly
We pass two flags to FFmpeg: -c:v copy tells it to stream-copy the video — same bytes in, same bytes out, no re-encoding — and -an drops the audio track entirely. The output is wrapped in MP4 because that is the most universally playable container, regardless of whether your input was MOV, WebM, or already MP4. Total time: usually a few seconds, even for long recordings, because we are just rewriting the container, not transcoding pixels.
No re-encode means no quality loss
This is the whole point. Most "mute a video" tools online quietly re-encode the video stream while they are at it, which means a generation of quality is lost every time. We do not. The picture in your output file is byte-identical to the picture in your input, just without the audio track riding alongside it. You can mute, edit, mute again, and never see the kind of compression artifacts that pile up when each step re-encodes.
Adjacent tools you might want next
If what you actually need is the audio extracted as a separate file (rather than dropped on the floor), use MP4 to MP3. If the file came out of a browser recording and is in WebM, run it through WebM to MP4 first. And if you are recording fresh, Clipy lets you record without the mic in the first place — which is the cleanest way to avoid this whole step.