Question 1

How do I trim a video online without uploading the file?

Accepted Answer

Pick the file and mark the start and end on the timeline. The trim runs in the browser, on your device's own processor, and the result is built in memory and downloaded directly. No byte of the video goes through a server, which also means there is no upload queue and no upload limit.

Question 2

What is the difference between fast cut and frame-exact cut?

Accepted Answer

Fast cut copies the compressed data without re-encoding: it takes seconds even for long videos and the quality is identical to the original, but it can only start on keyframes. Frame-exact cut decodes and encodes again: it cuts on the exact frame and allows removing the middle and rotating in any format, but it takes longer and produces a newly compressed file.

Question 3

Why does the fast cut start before the point I marked?

Accepted Answer

Frames that are not keyframes exist only as differences from earlier ones. For the first frame to play, the file must begin at the keyframe before it. The gap between keyframes differs from file to file; the tool reads the one in your video and shows how many extra seconds the file will have, with buttons to snap the start to the previous or the next keyframe.

Question 4

How do I remove a section from the middle of a video?

Accepted Answer

Choose Remove it, mark the part to take out and trim. The tool discards the frames and audio of that part and shifts the rest to close the gap, so the final length is the original minus the removed part. This mode always re-encodes; if the marked part touches the start or end of the video, it becomes a simple trim and fast cut applies again.

Question 5

Does trimming lose quality?

Accepted Answer

Fast cut does not: the frames are the same as the original. Frame-exact cut compresses the video again, which always has some loss; the tool uses a high bitrate (up to 1.2 times the original) so the difference is hard to notice. If quality is the priority and the start does not need to be exact, prefer fast cut.

Question 6

Which video formats work?

Accepted Answer

Reading covers MP4, MOV, WebM and MKV, among others. Preview and thumbnails depend on the browser playing the file's codec: H.264 plays almost everywhere, HEVC (H.265) only in some browsers. If the preview does not appear, fast cut still works by typing the times. Output is MP4 or WebM.

Question 7

Why does my browser not let me re-encode?

Accepted Answer

Re-encoding uses the WebCodecs API. Chromium-based browsers such as Chrome and Edge offer it; Safari and Firefox vary by version and platform, and support for encoding H.264, VP9 and audio differs between them. The tool tests your browser and tells you what is available. Fast cut does not depend on it.

Question 8

How do I remove the sound or rotate the video?

Accepted Answer

Turn on Remove the sound so the file has no audio track. To rotate, click Rotate 90° until the orientation is right; the rotation adds to the file's own. In MP4 with fast cut, the rotation is stored as a flag in the file, which most players respect; in other cases the video is redrawn already rotated.

Question 9

Is there a size or duration limit?

Accepted Answer

There is no fixed limit, but the result is assembled in browser memory, so files of several gigabytes can exhaust it. Videos of a few minutes and a few hundred megabytes usually work well. Frame-exact cut is the heaviest, because it processes every frame.

Question 10

Does it work on a phone?

Accepted Answer

Yes, in modern browsers. Fast cut works wherever the browser opens the file. Frame-exact cut depends on the device browser's WebCodecs support, which the tool checks. Handles are large enough for touch, and weaker devices take longer to re-encode.

Online Video Trimmer