Video Trimmer
Cut a video down to a specific start and end time, right in your browser.
About this tool
Cuts a video down to the start and end time you choose, without re-encoding — the trimmed section is copied out as-is, so it's fast and lossless. Drag either handle on the slider, or type an exact value (down to the millisecond) into the boxes below it — both stay in sync, and each shows a live preview of the exact frame at that point. Runs entirely in your browser using ffmpeg.wasm, a WebAssembly build of the real ffmpeg; your video is never uploaded anywhere.
The ffmpeg engine (about 32MB) is only downloaded the first time you use this tool, not when the page loads.
Frequently asked questions
- Why does my trimmed video start a fraction of a second earlier or later than I asked for?
- Because this tool copies video data directly without re-encoding (for speed), a cut can only happen at an existing keyframe — the actual start may snap to the nearest keyframe before your requested time rather than landing exactly on it. This is a well-known trade-off of fast, lossless trimming; frame-perfect cuts would require re-encoding, which is slower.
- Why did nothing happen for a while after I clicked trim?
- The first click downloads and initializes the ~32MB ffmpeg engine, which takes a moment depending on your connection. After that first load, trimming itself is fast.
- What format is the output?
- The same container/format as your input file — since no re-encoding happens, the video and audio streams are copied through unchanged.
- Is my video uploaded anywhere?
- No — the entire process, including the ffmpeg engine itself, runs locally in your browser via WebAssembly. Nothing is sent to any server.