Cut and trim a video, without uploading it

Why a fast cut starts on the next keyframe

A video file does not store every frame as a full picture. Every so often it stores a keyframe, a frame that can be decoded on its own, and the frames in between are stored as changes that rely on the frames around them (MDN). A cut that copies the video without re-encoding it has to begin on a keyframe, because the frames after your start cannot be shown without the keyframe before them.

So the fast cut starts on the first keyframe at or after the start you choose, and shows you that time before you cut. How far apart keyframes are depends on the phone, camera or app that made the video, which is why the timeline marks them. The end can be on any frame that does not depend on a later one, so it is your end or a frame or two before it.

Because nothing is re-encoded, the cut looks and sounds exactly like the original, keeps its quality and bitrate, and takes about as long as copying the part you keep. In our tests a 5 second cut from a 1080p video took well under a second.

Fast cut or exact cut

A cut can start on any frame only if the picture is encoded again from that frame. This cutter does both: Fast is selected when the page opens, and Exact frame is the other choice under How to cut. This is how they compare:

Fast suits most cuts: it is quick, lossless and starts at most one keyframe gap after your start. Choose Exact frame when the cut has to begin on a particular moment, such as the first word of a speech, or when the keyframes in your video are far apart, as in some screen recordings. Either way the new file holds nothing from before its start.

Why the cut never starts early

Some lossless cutters start at the keyframe before your start instead, and mark the extra seconds as hidden with an edit list inside the MP4 or MOV file. Players that follow the edit list skip the hidden part, but it is still in the file. FFmpeg, for example, follows edit lists by default and has an option to ignore them (FFmpeg). Anyone who uses that option can see what you cut off.

This tool never does that. Nothing before the start it shows you is stored in the new file, and it writes no edit list that hides frames, so every player begins on the same frame. Our guide on whether someone can see what you cropped or trimmed explains the other ways a trimmed video can give away its full length.

Trimming in the Photos app, and trimming here

The Photos app on an iPhone can trim a video too. Save Video keeps only the trimmed video in your library, Save Video as New Clip keeps both versions, and a trim saved with Save Video can be undone later with Revert (Apple). In other words, the trimmed part is kept in your library so you can get it back.

This tool makes a new file that holds only the part you keep. It does not change the original video on your device, and there is nothing in the new file to revert to. That makes it a good choice for a clip you want to send without the rest.

Trimming large video files

There is no upload, so a large video starts at once and meets no size cap from a server. Your browser fetches the video from your device in small pieces and copies only the part you keep, so a long recording is fine as long as the part you keep fits.

Results up to about 500 MB on a computer, or about 200 MB on a phone, are held in memory until you download them. Above that, Chrome and Edge on a computer write the cut straight into a file you choose, so it never has to fit in memory. Other browsers have to hold a big cut in memory, which can fail on a phone; the tool warns you first, and a shorter part always works.

Which videos and browsers work

You can open MP4, MOV, WebM and MKV videos, including iPhone videos recorded in HEVC, also known as H.265 (Apple). MP4 and MOV videos are saved as MP4, and WebM videos stay WebM; WebM to MP4 makes an MP4 of one afterwards. Copying needs no video decoder, so the fast cut works even when the browser cannot show the picture; the tool tells you when that happens, and you can set the times by listening or typing.

An exact cut decodes the picture and encodes it again as an H.264 MP4, so it needs a browser that can show the video and has a video encoder: Chrome, Edge, Samsung Internet, Firefox on a computer or Safari 26. When yours cannot, the tool says so before anything runs and offers the fast cut instead.

The cut leaves out the title, recording date, location and device details of the original, and a phone video shot upright still plays upright.