Trim a video
Cut a section out of a video in your browser without re-encoding it. Fast, lossless, and your file is never uploaded.
Your file is processed entirely in this browser tab. It is never uploaded, stored or seen by anyone.
To trim a video, drop it into the converter above and set a start and end time. The selected section is copied out without re-encoding, so it is both fast and completely lossless. Cut points snap to the nearest keyframe, which can shift them by a second or two.
How it works
- Choose your file
Drag a file onto the converter, or click to browse. Nothing is uploaded — the file is read directly by your browser.
- Convert to Trim
Press Convert. FFmpeg runs as WebAssembly inside the tab and shows real progress as it works.
- Download the result
When it finishes, download the Trim file. It is created in your browser's memory and never sent anywhere.
Your file never leaves your device — conversion runs entirely in this browser tab.
About Trim
Trimming with stream copy is the one operation in this toolkit that is genuinely lossless. Rather than decoding and re-encoding the video, it copies the compressed packets straight through, which means it runs in seconds regardless of clip length and the output is bit-identical to the corresponding section of the source.
The trade-off is precision. Video is not stored as independent frames — most frames describe only what changed since the last keyframe, so a cut can only start cleanly at a keyframe. Keyframes typically occur every two to ten seconds, so a requested cut point may shift by up to that much.
For most purposes that is fine. When you need frame-accurate cuts, the clip has to be re-encoded, which is slower and lossy — a worthwhile trade only when the exact frame genuinely matters.
| Codec | Stream copy — source codecs preserved |
|---|---|
| Container | MPEG-4 Part 14 |
| Typical bitrate | Unchanged from source |
| Compatibility | Matches the source file |
| Best for | Removing dead air, clipping highlights, splitting recordings |
Limits you should know about
Because conversion happens on your device rather than on a server, the ceiling is your browser's memory rather than our disk space. Files under 50MB work reliably everywhere. Desktop browsers stretch to roughly 200MB; mobile browsers, and iOS Safari in particular, cut out closer to 40MB.
Speed is the other trade. Running FFmpeg through WebAssembly is 5–10× slower than a desktop app, so a conversion that takes thirty seconds in a desktop application can take several minutes here. The converter shows a real estimate before it starts, and the tab has to stay open while it runs.
If your file is beyond those limits, trim it first, or use a desktop application such as HandBrake or FFmpeg directly — neither has a size ceiling.
Common questions
Why did my cut start a second early?
Stream copy can only cut at keyframes, which occur every few seconds. The cut snaps backwards to the nearest one so no frames are missing. Frame-accurate cutting requires re-encoding.
Does trimming reduce quality?
No. The compressed data is copied through untouched, so the trimmed section is identical to the source. This is the only operation here that loses nothing.
Why is trimming so much faster than converting?
Because nothing is decoded or re-encoded. The converter is only copying bytes, which is limited by disk speed rather than processing power.