Trim a video by start and end time
Enter where the clip should start and end. In the default mode the video data is copied without re-encoding, so quality is untouched and even long files finish in seconds; switch to re-encode for frame-accurate cuts. Runs on your device.
How to use the Trim Video
- Drop the video.
- Type the start and end times (for example 1:05 and 1:35).
- Leave frame-accurate off for an instant, lossless cut; turn it on if the cut must land on an exact frame.
- Click Trim and download.
Two ways to cut
Stream copy (default) slices the existing compressed video and audio streams without decoding them. It is lossless and fast, but video can only be cut at keyframes, which occur every 1–5 seconds in most files, so the actual start may be up to a few seconds before the time you typed; the player then fast-forwards to your start point. Frame-accurate mode decodes and re-encodes the selected range with H.264, so the cut lands exactly where you asked, at the cost of encoding time and a small quality loss (CRF 23, visually lossless).
Typical uses
- Cutting the dead air at the start and end of a screen recording.
- Extracting one answer from a recorded interview.
- Making a 30-second excerpt to send on WhatsApp instead of a 5-minute file.
- Removing a section before sharing a family video.
Formats
Stream copy keeps the original container (MP4 stays MP4, MOV stays MOV, MKV stays MKV). Frame-accurate mode always outputs MP4 with H.264 and AAC, which plays everywhere. To convert containers without trimming, use the video converter.
How it runs without uploading
This tool uses ffmpeg, the same open-source engine behind most video software, compiled to WebAssembly. The first time you use a video tool the engine (about 30 MB) is downloaded from a content delivery network and cached by your browser; after that it loads instantly, even offline. Your video is read into memory, processed by the engine inside the browser sandbox, and the result is offered as a download. Nothing is transmitted. Because it runs on one CPU core, encoding takes roughly real time to three times real time depending on your device: a 30-second clip takes 30–90 seconds, a 10-minute video may take 10–30 minutes and needs a few hundred megabytes of free memory. For long videos, trim first or use a desktop tool.
Frequently asked questions
Why does my cut start slightly early?
Stream-copy mode cuts at the nearest keyframe before your start time. Enable frame-accurate mode for an exact cut.
Does trimming reduce quality?
Not in stream-copy mode. Frame-accurate mode re-encodes at a visually lossless setting.
Can I remove a section from the middle?
Trim the two parts you want to keep as separate files; a join tool is planned.
Privacy
This tool runs entirely inside your browser using WebAssembly and the Canvas/File APIs. Your files are never uploaded to ToolFlint or any third party; you can verify this in your browser's network tab or by switching to airplane mode after the page loads. Read how we process files.
Last updated 2026-09-23.