ALL VIDEO TOOLS23
Video Trimmer
Trim Video Online — Free Video Cutter
Upload a video, set start and end times, and download the trimmed clip instantly.
About Video Trimmer
Need to cut a section from a video? Whether you are extracting a highlight from a long recording, clipping a specific scene for a presentation, trimming the beginning and end of a screen recording, or isolating a moment to share on social media, this tool makes it quick and easy. Upload your MP4, WebM, MOV, AVI, or MKV file and use the built-in video player to preview the content and set the start and end times. Download just the clip you need in the same format as the original, preserving video and audio quality. The trimming uses stream copy mode (no re-encoding), which means processing is near-instant regardless of the video length — it simply extracts the selected segment from the container without touching the compressed video data. This preserves the original resolution, bitrate, and quality exactly. The trade-off is that a stream copy can only cut on a keyframe, so the clip starts at the nearest keyframe at or before the time you picked — usually within a second or two, and frame-accurate cutting would require a full re-encode. Powered by FFmpeg.wasm running entirely in your browser via WebAssembly, so no video files are uploaded to any server. This makes it safe for trimming confidential meeting recordings, personal videos, and proprietary content.
Questions
What video formats can I trim?
MP4, WebM, MOV, AVI, and MKV. The trimmed output uses the same format as your input.
Is the video re-encoded when trimming?
No. The tool uses stream copy mode (-c copy) which copies the video and audio data without re-encoding. This is nearly instant and preserves original quality.
Why doesn't the trim start exactly where I set it?
Stream copy mode can only cut at keyframes. The actual start time may be slightly before your requested time. For frame-accurate trimming, re-encoding would be needed.
Why is there a 1.5 GB limit?
Because trimming keeps the original quality, the trimmed copy can be as large as the source — and it has to be held in the tab, where a browser tops out around 1.8 GB for a single file. If you only need the sound, MP4 to MP3 reads the video in place and has no size cap.
Why does the first trim take longer than the next one?
The first run loads the FFmpeg engine — a ~31 MB WebAssembly download served from this site's own origin — and keeps it in memory afterwards. The trim itself is a stream copy, so even a 1.5 GB file finishes in about 15 seconds once the engine is up.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.