Video trimmer

How to use the video trimmer

1. 01Choose your video file, or drop it onto the box.
2. 02Type a start and an end time, as seconds (12.5) or minutes and seconds (1:05).
3. 03Choose Fast for a cut without re-encoding, or Precise for a frame-exact cut.
4. 04Check the plan line, then click Trim video and download the result.

Fast or Precise: which cut to choose

Fast copies the video and sound as they are, so it takes moments and loses nothing. The catch is keyframes: a copy has to begin at a complete picture, so the trimmer starts the copy at the keyframe at or before your start time and hides the frames before the cut with an MP4 edit list. The cut falls where the frame on screen at your start time begins, so in Chrome the clip starts on that frame, up to one frame before the time you entered, with the sound cut at the same moment. A player that ignores edit lists shows the extra frames before the cut, so in some players the clip can start early by as much as the gap between two keyframes, and the end can run a fraction of a second past the time you set.

Precise re-encodes the video to H.264 and any sound to AAC (or VP9 and Opus in WebM when your browser cannot make MP4), so both cuts land on the exact frame. It is slower, and like any re-encode it costs a small amount of quality. Choose it when the first or last frame matters, for example when the clip will be joined to another, or will be played somewhere you cannot test.

Fast is only a copy when your file's codecs can go into MP4 as they are: H.264 or HEVC video, with AAC or MP3 sound or none. For any other file the trimmer re-encodes whichever option you pick, and the plan line above the button says so before you start. Re-encoding needs your browser to decode the video first; if it cannot, the trimmer says so under the button, which stays disabled, before you start.

Typing start and end times

Both times accept plain seconds with an optional decimal, such as 12.5, or minutes and seconds, such as 1:05 or 1:05.25. Longer clips can use hours as well, as in 1:02:30. The end time starts at 10 seconds, or at the end of the clip for anything shorter.

The end must come after the start and fall inside the clip, and a trim must keep at least a tenth of a second. If a time is outside those limits, the tool tells you what to change and keeps the button disabled until it can run.

When a trimmed clip looks wrong in another app

If a fast-trimmed clip plays correctly in Chrome but starts early in another player, that player is ignoring the MP4 edit list and showing the frames between the keyframe and your cut. The file itself is intact. Trimming the same clip again with Precise re-encodes it, and the result starts exactly on your chosen frame in every player.

The same applies when a fast-trimmed clip goes on to another edit. The looper here, for example, spots that hidden lead-in and, where your browser can decode the clip and encode video, re-encodes the clip once before repeating it, rather than repeating the extra frames with every play.

Questions about the video trimmer

Does trimming a video lose quality?

Not with Fast, when your file's codecs can go into MP4 as they are: the video and sound are copied without re-encoding. Precise re-encodes, which costs a small amount of quality in exchange for a frame-exact cut.

Why does my fast-trimmed clip start a little early?

A fast cut starts on the frame that is on screen at your start time, so even in Chrome it can begin up to one frame early. A copy also has to start at a keyframe, so the file begins at the keyframe at or before your start time, with the frames before the cut hidden by an MP4 edit list. Chrome respects it; a player that ignores edit lists shows those frames. Use Precise for a frame-exact start in every player.

What formats can I trim?

Most video files your browser can read, such as MP4, MOV, MKV and WebM. The fast copy needs H.264 or HEVC video with AAC or MP3 sound; anything else is re-encoded to MP4, or to WebM if your browser cannot make MP4, provided your browser can decode it. GIFs are not accepted: convert one to MP4 first.

Is my video uploaded?

No. The trim runs in your browser; your video, and the clip you cut from it, never leave your device.

More free tools

Updated 23 September 2026 · All free tools