Toolrack

Video Trimmer

Works offlineNothing is uploadedFree, no sign-up
Drop a video hereor click to choose — MP4 and MOV, any length

Opened, cut and saved on your device. The video is never uploaded.

Cut a piece out of an MP4 without re-encoding it: drag the two handles, and the clip is copied out frame for frame in about a second, at the quality it already had. You can also pull stills out of the selection as PNG or JPEG. The video is opened and rewritten on your device — nothing is uploaded, and nothing is sent anywhere.

The keyframe ticks are drawn along the timeline rather than mentioned in a note afterwards, because the compromise in a fast cut is entirely about where those frames sit. An editor that hides them appears to honour any start you drag to and then quietly hands back something else; showing them turns the same limitation into a thing you can aim at. The start moving backwards rather than forwards follows from the same idea — extra footage is visible and removable, missing footage is neither.

Frequently asked questions

Why does my clip start slightly earlier than I asked?

Because a cut can only begin on a keyframe. In an MP4 only some frames are stored whole; the rest are stored as differences from the frames around them, and a clip that began on one of those would open to a smear of colour until the next whole frame arrived. The start therefore moves back to the nearest keyframe, never forward — backward gives you a little extra footage you can see and trim again, while forward would silently throw away part of what you chose to keep. The ticks along the bottom of the timeline are the keyframes, and the readout says how far the start had to move.

Is the video re-encoded?

No, and that is the whole point. The already-encoded frames are copied straight from one container into the other, so there is no generation loss and no waiting: a clip out of a long file is written about as fast as the file can be read. Re-encoding would let the cut land on any frame at all, but it would also take minutes, heat the machine, and make the clip visibly worse than the original.

What happens to the sound?

The audio samples covering the same span are copied across with the picture, in the same way and with the same quality. If the file has no audio track, the clip has none either, and the file panel says so before you cut.

Which files does it open?

MP4 and MOV holding H.264 or H.265 video — which covers phone recordings, screen captures and almost everything downloaded from the web. Formats built on a different container, such as MKV or WebM, are not read here: their index is laid out differently, and reading them would mean shipping a second demuxer to every visitor for the rarer case.

How large a video can it handle?

The file is held in memory while it is being cut, so the real limit is the memory a browser tab is allowed rather than a number this page sets. It needs roughly twice the file's own size while it works: a 300 MB 4K recording off a phone opens in well under a second and cuts in about one, which is the largest thing this has been measured against. Multi-gigabyte files are where a tab starts to struggle. Nothing is streamed to a server to get around that, because nothing is sent to a server at all.

Is anything uploaded?

No. The file is read, taken apart, cut and packed back together inside the page. It works with no connection at all, which is the simplest proof that nothing leaves the device.

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