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Video Trimmer

Cut a clip out of a video. A copied cut leaves the picture exactly as it was, and nothing is uploaded.

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Cut a clip out of a video

The part of the video to keep

The timeline fills in when you add a video

Read only when the cut is re-encoded. A copied cut keeps the original picture exactly, so there is nothing to choose.

How the clip is written
Commandffmpeg -i input.mp4 -c copy -avoid_negative_ts make_zero clip.mp4
Choose a video to start

How it works

  1. 01

    Open a video

    Drop it or choose it. It plays here first, so you can see what you are cutting.

  2. 02

    Set the two ends

    Drag the handles or type the timecodes. The player follows the handle you move.

  3. 03

    Save the clip

    The file downloads when it is written. A copied cut takes a second or two.

Copy the cut, or re-encode it

Copying is the default. The original video packets are put into a new file without being decoded. The picture is the one you started with, and a long video is done in a second or two.

The catch is keyframes. A video stores a full frame only every couple of seconds. The frames between it are written as changes from that one, and mean nothing without it. So a copied cut has to begin on a full frame, and it lands on the nearest one behind the handle you set.

Turn on re-encode when the cut has to be exact. The clip is decoded and written again, frame by frame, so it starts where you asked. That takes about as long as the clip lasts, and the picture goes through one more round of compression.

Try a copy first and watch the result. Most cuts are for a person, not a frame counter, and a second either way does not show.

Input
MP4, MOV, MKV, WebM and AVI. One video at a time.
Output
The format you gave it, or an MP4 when you re-encode.
Engine
ffmpeg, built for the web, running in this tab.
Limits
No watermark, no length cap, no daily count.

What comes out, and how big

A copied clip keeps the format it came in as. A MOV stays a MOV, an MKV stays an MKV, and the codec inside is untouched. Re-encoding always writes an MP4 with H.264 video and AAC sound, which is the pair that plays on every phone, browser and television.

The figure under the buttons is a fair guess for a copy. The bits are spread evenly through the source, so keeping a third of the running time keeps about a third of the bytes. Re-encoding gets no figure at all, because the size depends on how much moves in the part you kept.

This tool cuts. It does not set out to make a file smaller, and a trim on its own rarely does much. If the clip still has to fit an email or a chat limit, send it through the video compressor afterwards.

Sound is kept in step with the picture on both paths. Turn it off and the clip is written silent, which is smaller and often what a background loop wants.

Frequently asked questions

Is my video uploaded?
No. The page reads it from your disk and cuts it on your own processor. There is no upload to wait for, and the tool still works with the network off.
Why is the cut a second away from where I set it?
A copied cut can only start on a full frame, and a video stores one every couple of seconds. Turn on re-encode and the clip starts on the frame you chose.
Is there a size or length limit?
None that we set. Your browser holds the file in memory while it works, so a very large video can run a tab out of room. A phone gives up sooner than a laptop.
Does trimming lose quality?
A copied cut loses nothing. The frames are moved, not re-drawn. Re-encoding costs a little, and the quality setting says how much.
Which formats can I trim?
MP4, MOV, MKV, WebM and AVI. The clip comes back in the same format unless you re-encode it, which writes an MP4.
Can I take several clips out of one video?
One at a time. The video stays loaded after a download, so set the next range and press the button again.
Why is a re-encode so much slower?
It decodes every frame you kept and writes it again, on your machine. A copy moves the frames as they are. That is the whole difference in speed.
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