How to Cut a Video Without Losing Quality (and Why the Cut Can Start a Bit Early)

Updated November 3, 2026

Cutting a video sounds simple — keep the part you want, throw away the rest — but there are two very different ways to do it. One copies the video untouched and is instant; the other rebuilds every frame. Knowing which one you get explains why a cut can start a moment early, and how to keep the full quality.

1. Two ways to cut: copy or re-encode

Copy (lossless). If you only cut and keep the format (an MP4 stays MP4), the frames are copied as they are. Nothing is compressed again, so the quality is exactly the original's and even a long video is done in seconds.
Re-encode. If you also change the size, the frame (9:16, 1:1…), the speed or compress the video, every frame has to be drawn again and encoded. The cut is then exact to the frame, but each new encoding loses a little detail.

2. Why a copied cut can start a little early

A compressed video does not store every frame whole. It stores a full picture now and then — a key frame, often every second or two in phone videos — and, in between, only what changed. A frame in the middle cannot be shown without the key frame before it, so a copied cut has to start at a key frame, a moment away from where you marked it.

If you need the cut to start on an exact frame — a speech that must not begin mid-word, a clip that loops — change something that forces a re-encode (lowering the size to 1080p is enough), or leave half a second of margin before the moment you want.

3. Marking the start and end precisely

Drag the two handles on the timeline; it shows frames of the video so you can see where you are.
Play the video and press Start here and End here at the right moments.
Type the times, such as 1:23.5 (1 minute, 23 and a half seconds).
Select a handle and use the arrow keys for small steps.
Press Play the cut before exporting, to hear the first and last words.

4. Turning it vertical for Reels, TikTok and Status

A horizontal 1920 × 1080 video has two ways to become 9:16:

Fill: keeps the centre of the picture and cuts the sides — the result is 608 × 1080, about a third of the width. Good when the subject is in the middle.
Whole picture: keeps everything and adds black bars above and below. Nothing is lost, but the video is small on the screen.

Square 1:1 works the same way: Fill keeps the 1080 × 1080 centre.

5. Sound and format

You can keep the sound, remove it (a clip for a presentation) or keep only the sound (the audio of a lecture).
MP4 plays on every phone, computer and app. MOV, WebM and MKV are there when a program asks for them.

Cut your video

In the video cutter, drop the video, drag the two handles, play the cut and export an MP4 — no watermark, no sign-up. The video is processed by your browser and never leaves your device.

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