Video Trimmer
Cut a clip down to the part you actually need. Stream copy does it in seconds without re-encoding a single frame — or switch to precise mode when the cut has to land exactly.
MP4 · MOV · MKV · WebM · AVI — nothing is uploaded, and the original stays untouched
Playhead 0:00.0
Accepts plain seconds (12.5) or a clock value (1:02.5).
Two ways to cut, and why the choice matters
A video is not a sequence of independent pictures — most frames are stored as differences from a nearby keyframe, and only keyframes stand alone. Stream copy cuts without decoding: FFmpeg seeks to the nearest keyframe and simply copies the compressed data into a new file. It takes a second or two regardless of length, produces byte-identical picture quality, and is the right answer almost every time. The trade-off is that the cut snaps to the nearest keyframe — typically within a couple of seconds on camera footage.
Precise mode re-encodes instead. FFmpeg decodes from the previous keyframe, discards frames before your start time and encodes a fresh stream, so the cut lands exactly where you asked. It costs time — comparable to converting the whole clip — and it is lossy on top of whatever compression the file already had. Use it when the exact frame is the point, such as cutting to a beat or to a spoken word.
Cut first, then compress
If you are preparing a clip for the web, trim before you compress. Cutting a 10-minute video down to the 30 seconds you need reduces the work for the compressor by an order of magnitude, and in stream-copy mode there is no quality cost at all for doing so. It is the cheapest real optimisation available in video work.
Two small details worth knowing: the timestamps of the trimmed file are rebased to start at zero, so it plays from the beginning rather than seeking to an offset; and because stream copy cannot change codecs, the container stays the same as the source. If you need a different format, cut here and then run the result through the converter.
FAQ
Why did my cut land a second or two early?
That is stream copy snapping to the nearest keyframe. Switch to precise mode to land on the exact frame — it will re-encode and take longer.
Does trimming reduce quality?
In fast mode, not at all — the video data is copied untouched. In precise mode the clipped range is re-encoded, so there is a small generation loss unless you raise the quality.
Is the original file modified?
Never. The result is a new file you download; the file on your disk is only read.