Why You Need This
Every time a video is re-encoded it loses a small amount of quality. If you only need to shorten a clip there is no reason to degrade the image. Unfortunately most editors force a full re-encode even for a simple trim, which costs both quality and time.
Lossless trimming works by copying the existing compressed data from the input file into a new container without decoding or re-compressing. The result is bit-for-bit identical to the original within the selected range. This is the same principle behind the FFmpeg -c copy flag.
FastCut Pro brings this capability to the browser. You get instant, zero-quality-loss trims on any device without installing software. The entire operation typically completes in under a second regardless of file size because no transcoding takes place.
Step-by-Step Guide
- Step 1: Navigate to fastcut.cc and drop your video file onto the editor.
- Step 2: Wait for the waveform to render. This analysis step reads only the audio track and is very fast.
- Step 3: Position the start and end handles on the timeline. Use the zoom slider to get frame-level precision.
- Step 4: Ensure the export mode is set to Lossless (-c copy). This is the default and will skip re-encoding entirely.
- Step 5: Click Export. The browser writes the trimmed segment to a new file in milliseconds.
- Step 6: Your download begins automatically. Open the file to verify the trim is exactly where you wanted it.
Why Use FastCut Pro
- No Upload Required — Your footage stays local. There is no waiting for cloud servers to process your trim.
- Lossless Quality — Stream data is copied byte-for-byte so there is zero generation loss.
- 100% Free — Unlimited lossless trims with no watermark or file size cap.
- Privacy First — Nothing is transmitted over the network. Your video is processed entirely on your own hardware.
Pro Tips
- Lossless cuts must land on keyframes. FastCut Pro automatically snaps to the nearest keyframe so you always get a clean cut.
- If you need a frame-exact cut that does not align with a keyframe, switch to re-encode mode for just that segment.
- Check the export summary panel to confirm the output codec matches the input. This guarantees no transcoding occurred.