Cut a section out of a video online

How to cut part of a video in your browser

1. 01

   Open the file

   Drag your video onto the drop zone above, or click it and pick a file. MP4, MOV, MKV, WebM and AVI are all read directly. Nothing is transmitted — the browser just opens the file off your disk.

2. 02

   Find the part you want to remove

   Scrub the player to the moment the unwanted section starts. Clicking the timeline seeks the preview, so you can find the exact frame before you commit to anything.

3. 03

   Add a cut

   Right-click the timeline at that point and choose Cut, or press "+ Add edit" with the playhead where you want the cut to begin. A red band appears on the timeline.

4. 04

   Set the range precisely

   Drag the two handles to cover exactly the section you want removed, or type the start and end seconds into the card. Repeat for every other section you want gone.

5. 05

   Apply and download

   Press Apply All Edits. Every cut is turned into one filter graph and run in a single pass, then the finished file appears as a download link.

Trimming the ends versus removing the middle

"Trim" usually means cutting away the start or the end of a clip, and "cut" usually means taking a chunk out of the middle. Both are the same operation here: you mark a range and it disappears. To trim the first eight seconds of dead air off a screen recording, add a cut from 0 to 8. To lose a fumbled sentence at 2:14, add a cut from 2:14 to 2:19. To do both, add both — they are applied together.

If what you actually want is one section with everything around it gone, mark that section and press "Keep only this part" — the editor adds the cuts before and after it for you; trimming a video to one section covers that route.

What you cannot do is reorder what is left. The segments are re-joined in the order they appeared in the source. This is a trimmer, not a multi-track non-linear editor.

If you are cutting towards a number rather than towards a feel — getting a clip under a hard duration limit for a Reel, a Short or a status post — the editor shows an estimated output length that updates as you drag the handles. Trimming a video to a specific length covers that workflow, including what to do when there is nothing left to cut and you are still a few seconds over.

What FFmpeg actually does to remove a section

Each surviving piece of the video is passed through FFmpeg's trim filter — one for everything before the cut, one for everything after it. Each piece then has its presentation timestamps rebased to zero with setpts=PTS-STARTPTS, because otherwise the second piece would still believe it starts at 2:19 and the player would sit on a black frame waiting for it. The audio side gets the same treatment with atrim and asetpts. Finally the pieces are glued back together with the concat filter.

Because the frames go through a filter graph, they have to be re-encoded on the way out — you cannot copy a stream you are also modifying. That is the honest cost of an exact cut: a keyframe-only cut would be lossless but would land at the nearest keyframe rather than where you asked, which on a screen recording can be several seconds away. The full pipeline is written up here.

Cutting MP4, MOV, MKV, WebM and AVI

The input container barely matters: FFmpeg demuxes MP4, MOV, MKV, WebM and AVI alike, so a cut works the same on a phone recording, an OBS capture and an old AVI. The output container is your choice. MP4, MKV and MOV come out as H.264 video with AAC audio — the safest thing to hand to anyone. WebM comes out as VP8 with Opus, which encodes noticeably slower in WebAssembly, so only choose it if you specifically need a WebM file.

If the source has no audio track at all, the cut still works; FFmpeg is retried without the audio branch of the filter graph and you get a valid silent video back.

Questions about cutting video online