BuzzKit
Video Trimmer
Set a start time and duration to cut a clip down to exactly the part you need.
Trimming uses stream copy where possible, so it's usually much faster than a full re-encode.
What this tool is for
A recording is often longer than the part you actually want — a screen recording with a slow start, a phone video with a boring stretch before the important moment. This tool cuts a video down to just the section you specify, by start time and duration, without needing a full video editor.
It's for pulling out a specific clip from something longer: extracting a highlight from a recording, trimming dead air off the start or end, or preparing a short clip before joining it with others in Video Merger.
How the video trimmer works
You give the tool a start time and a duration in seconds, and it tells ffmpeg to seek to that point and cut out exactly that length. When the format allows it, ffmpeg copies the existing video and audio stream directly rather than decoding and re-encoding it, which is both fast and lossless — the trimmed section keeps the exact same quality as the source, since nothing was re-compressed.
Stream copying like this has one technical wrinkle worth knowing: video is stored as a sequence of frames where most frames only record the change since a recent full frame, called a keyframe, so a lossless cut can only start cleanly at a keyframe. If your requested start time falls between keyframes, hitting that exact point precisely can require re-encoding a short portion rather than a pure lossless copy. In practice this is rarely noticeable, but it's why frame-perfect trims aren't always guaranteed to be bit-for-bit lossless.
Common situations this solves
- Pulling a highlight out of a longer screen or phone recording.
- Cutting dead time off the start or end of a clip before sharing it.
- Preparing several short clips to join together afterward with Video Merger.
Limitations, honestly
This tool trims one continuous section per run — to keep several separate sections from the same source, run it again for each one and merge the results afterward. Very precise, frame-accurate cuts at an arbitrary point can occasionally require re-encoding rather than a pure lossless copy, as explained above. And like the other tools here, processing happens in your browser tab, so a very long source file takes proportionally longer and uses more memory than a short one.
Frequently asked questions
How precise is the cut?
It follows the values you enter in seconds, down to a tenth of a second.
Can I trim multiple sections at once?
Not in one pass — run the tool again with a new start time for each section you need.
Will the quality change?
No — when possible the trim copies the original stream without re-encoding.
Do I need to know the exact timestamp before I start?
Preview the video in the tool first to find the moment you want, then enter that time as your start point — there's no need to know it in advance.
Does trimming re-encode the audio too?
No — audio is carried through unchanged in the same stream-copy process as the video, so its quality isn't affected by trimming.
What format is the trimmed file?
Always MP4, regardless of the source container, matching the format used elsewhere on the site.