Trim Video
Processed locally in your browser — nothing is uploaded.
Quick answer
To trim a video, set a start and an end point and keep only the clip between them — everything before and after is discarded. This tool does it in your browser with ffmpeg.wasm and, wherever possible, copies the video stream without re-encoding, so the trim is fast and loses no quality. Nothing is uploaded. A one-time ~32 MB engine loads on first use; short clips work best.
How to trim video
Load your video
Drop an MP4, MOV, WebM, MKV or AVI in. The first use downloads and caches the ~32 MB engine; later uses start immediately.
Set start and end
Scrub to where the clip should begin and end, and set the in and out points. Play across them to check you have the right moment.
Export the clip
Export and download just that segment. With stream copy it finishes almost instantly and the picture is untouched.
What does trimming keep?
Trimming is a keep operation: you define one region and everything outside it is thrown away. That is the opposite of cutting a chunk out of the middle and rejoining the sides. For topping and tailing — dropping the fumbling at the start and the walk-off at the end — trimming is exactly the tool. Because the kept range is copied straight through, it is both fast and, on a stream copy, perfectly lossless.
Why is stream copy fast and lossless?
Normally editing a video means decoding every frame, changing it, and re-encoding — slow, and each re-encode sheds a little quality. A stream copy (ffmpeg’s -c copy) skips all of that: it lifts the already-encoded frames out of the source and drops them into a new file byte-for-byte. No decode, no re-encode, no quality loss, and it runs in seconds even on a long clip because there is no math to do.
| Stream copy (-c copy) | Re-encode | |
|---|---|---|
| Speed | Near-instant | Slow (single-threaded here) |
| Quality | Identical to source | Slight loss |
| Cut precision | Snaps to a keyframe | Exact frame |
| Best for | Quick, lossless clips | A cut on an exact frame |
For most clips the keyframe snap is invisible — a fraction of a second either way — and well worth the speed and quality. When you need the cut on a precise word or action, choose the re-encode option and accept the slower, single-threaded pass.
How big a video can you trim in the browser?
Trimming by stream copy is light, so it handles longer files than the tools that re-encode — the work is mostly copying bytes, not crunching frames. Even so, the whole file is loaded into the tab’s memory, so a multi-gigabyte source can still run the browser out of room. If you plan to re-encode for an exact cut, treat it like the other editors and keep the clip short.
Is my video uploaded to trim it?
No. The trim is performed by ffmpeg.wasm inside your tab — your file is read into memory, sliced and returned as a download, never sent anywhere. Confirm it in DevTools → Network: trimming a file makes no upload request, and it works offline once the page has loaded. Ideal for unreleased and confidential footage.
Related video and audio tools
Need to keep several pieces? Trim each and then merge the clips. Want a square or vertical frame from your clip? Crop the video. Turning the trimmed moment into a loop? Make a GIF. And if you only want the sound from your selection, extract the audio as MP3 after trimming.
Your files never leave your device
Processed locally in your browser — nothing is uploaded. You can verify it yourself: open your browser’s developer tools, watch the Network tab, and use the tool — no upload request is ever made.
Frequently asked questions
Does trimming a video reduce its quality?
Not with a stream copy. The kept frames are copied straight from the source without re-encoding, so the clip is identical in quality to the original. Only the re-encode option, used for exact-frame cuts, touches quality at all.
Why does my clip start slightly before where I set it?
A stream-copy trim can only begin on a keyframe, so the in-point snaps to the nearest one. Choose the re-encode option if you need the cut on the exact frame you picked.
Is trimming faster than compressing?
Much faster. A stream-copy trim just copies existing frames, with no encoding, so it finishes in seconds even on long clips. Compression re-encodes every frame and is far slower.
What format does the trimmed clip come out as?
The same container and codec as the source when stream-copying, so an MP4 stays an MP4 with its original quality. That is part of why the trim is lossless.
Can I trim out the middle of a video?
Trimming keeps one continuous region and drops the ends. To remove a middle section and rejoin the two sides, trim the two keeper pieces separately and merge them.
Can I trim a long recording?
Yes, more comfortably than with re-encoding tools, because stream copy is light work. The limit is memory: the whole file loads into the tab, so extremely large sources can still run out of room.
Is the trim done privately?
Yes. It runs entirely in your browser via ffmpeg.wasm. Nothing is uploaded — you can verify there is no network request in your developer tools.