LosslessCut: trim video in seconds without re-encoding

Your drone, GoPro or lecture recorder fills up with tens of gigabytes, and trimming ten seconds off the front means opening an editor, importing, and waiting through a re-encode that costs quality. LosslessCut, an open-source project by Norwegian developer mifi, wraps FFmpeg’s stream-copy mode in a cross-platform GUI: a cut is a direct data-stream copy instead of a re-render, so trimming takes seconds and the output quality is identical to the source. The repo had 44,361 stars as of October 8, 2026; v3.69.0 shipped on June 4.

Core features

• Lossless video cutting: the region between your in and out points is stream-copied, not re-encoded — fast, and the picture comes out untouched where a normal editor re-renders every cut.
• Lossless merge and rearrange: segments with matching codec parameters (say, everything from one camera) concatenate and reorder directly; remuxing MKV to MP4 skips transcoding too.
• Track-level editing: combine video, audio and subtitle tracks across files, drop tracks you don’t need, extract audio, and edit metadata, chapter marks and rotation flags.
• Detection helpers: automatic black-scene, silent-audio and scene-change detection, keyframe-snapped timeline jumping, and a map view for the GPS track embedded in DJI footage.
• Automation hooks: a basic CLI and an HTTP API, plus import/export for CSV/EDL, DaVinci and Final Cut chapter marks, so it slots into batch workflows.

Typical use cases

• Rough-cutting camera, GoPro or drone footage: drop the dead takes and reclaim tens of gigabytes in one pass.
• Removing ads and intros from recordings, converting TS to MP4 along the way.
• Attaching external audio and subtitle tracks, pulling the music out, or fixing a wrong rotation flag without opening an editor.

Quick start

On macOS:

brew install --cask losslesscut

Or grab the DMG, AppImage or Windows 7z from the releases page. Drop a video in, mark in and out points with the I / O keys, hit Export, and a new file appears in seconds. The paid Mac App Store and Microsoft Store builds are functionally identical — buying one is a good way to fund the maintenance.

Summary

For large files that only need physical cuts, LosslessCut has little competition; it is not the tool for effects, transitions or color work — it pairs well with Recordly, which handles the look of screen recordings. GPL-2.0, written in TypeScript (Electron), maintained by one person. Two limits to know up front: cut points snap to keyframes, so frame-exact trims need the experimental smart cut (which partially re-encodes); and preview playback depends on what Chromium decodes natively, so HEVC and friends need an FFmpeg-generated low-res preview — the export still reads the original file, so nothing about the cut is lossy.