Cut a clip down to just the part you need — trimmed right on your machine with ffmpeg compiled to WebAssembly. Your file is never uploaded.
This tool runs a WebAssembly engine and needs to be opened over a local server, not straight from a file.
In this folder run python3 -m http.server 8777, then visit http://localhost:8777/trim.html.
First trim downloads the ~32 MB engine once (served by this site; processing stays on your device).
Drop a video or audio file, or click to choose
MP4, MOV, WebM, MP3, WAV, M4A… — stays on your device