Trim Video

Trimming Video Without Losing Quality

Trimming is the most common video edit there is: cutting away the dead air at the start, lifting a single highlight out of a long recording, or shortening a clip to fit an upload limit. What most people don't realize is that there are two fundamentally different ways to make that cut, and they behave very differently in terms of speed, precision, and quality.

Stream copy: fast and lossless

The default method is a stream copy. It doesn't decode or re-compress anything; it just copies the existing frames between your two timestamps into a new file. Because the original data is untouched, the result is perfectly lossless and the export takes a second or two even for a long source. The one catch is precision, and it comes down to keyframes.

Why keyframes limit where you can cut

To save space, video only stores a full image every so often — a keyframe— and describes the frames in between as changes from it. A stream copy can only start a clean cut on one of those keyframes, so your chosen start time snaps to the nearest one and may be a fraction of a second off. For rough cuts this is invisible; for a precise in-point it can matter.

When to use frame-accurate mode

Turning on frame-accuratemode re-encodes the clip so the cut lands exactly on the frame you asked for. It is slower and adds a negligible amount of re-compression, but it's the right choice when timing is critical — syncing to audio, cutting mid-word, or stitching clips together. For everything else, the fast stream copy gives you an instant, quality-perfect trim.