Why mute a video
The most common reasons: stripping copyrighted background music before a social-media upload to avoid takedowns, removing bystander conversations from family or street footage, prepping a clip for narration in a video editor, or creating a silent reference clip for a DAW where you want full control over the audio.
Why this is instant
The muter doesn't re-encode the video. It uses ffmpeg's stream-copy mode (-c copy -an) which simply repackages the video track into a new container and drops the audio stream. There's no quality loss because no encoding is performed — and the operation runs at file-copy speed regardless of how long the video is.
Need to mute only part of a video?
This tool removes audio from the entire clip. For partial muting (e.g. silencing one section but keeping the rest), use a desktop editor like Shotcut, DaVinci Resolve, or iMovie — those let you keyframe audio levels along the timeline.