How it works

Scrub the video, drag the handles, hit trim. Output is MP4, with a choice between stream-copy (fast) and re-encode (frame-accurate).

Drop any video the browser can decode. Use the trimmer to set start and end. Two modes. Stream copy is instant: ffmpeg just copies the compressed bytes between the chosen times, no re-encoding, no quality loss. The catch is that cuts snap to the nearest keyframe (typically every 1-5 seconds for H.264), so the trim may start a fraction of a second earlier than you set. Re-encode H.264 takes longer but cuts exactly at your chosen frame, producing a fresh H.264 / AAC MP4 at CRF 23. Pick re-encode when timing matters (memes, edits), stream-copy when you just need to chop a long video down. Built on ffmpeg.wasm, runs locally. Output filename has -trimmed.mp4 appended.

How to use it

1. Drop your video. Any format your browser can decode loads into the trimmer.
2. Set the cut points. Scrub the preview and drag the handles to mark start and end.
3. Pick a mode. Stream-copy is instant with zero quality loss but snaps to keyframes; re-encode cuts on the exact frame.
4. Trim and download. The -trimmed.mp4 is produced locally by ffmpeg.wasm and downloads.

Frequently asked questions

What's the difference between stream-copy and re-encode?

Stream-copy is instant but cuts snap to keyframes (so the trim may be a fraction early). Re-encode takes longer but cuts exactly at your chosen frame.

Will I lose quality when trimming?

Stream-copy: no quality loss at all. Re-encode: minor loss from a fresh H.264 pass at CRF 23 (close to source quality).

What output format do I get?

MP4 with H.264 video. Audio is copied (stream-copy mode) or re-encoded as AAC at 128 kbps (re-encode mode).

Is the video uploaded?

No. ffmpeg.wasm runs in your browser, the file never leaves your device.