Trimming is the most common video edit there is: cut the shaky start, drop the accidental ending, extract the one moment that matters. Yet many online services return a noticeably worse-looking file after a simple cut. Let's see why that happens and how to trim truly losslessly.
Where the quality loss comes from
Video is stored compressed. When a service trims a clip the naive way, it fully unpacks the video and compresses it again — that is called re-encoding. Every re-encode is like a photocopy of a photocopy: the picture gets a little blurrier, motion artifacts creep in. If the source is already heavily compressed (phone footage always is), the loss is visible to the naked eye.
Trimming without re-encoding
There is an honest way: leave the compressed frames untouched and simply copy the piece you need from one file into another. Quality cannot change — the bytes are the same. That is how our trim tool works by default: set the start and the end, and get the result in seconds even for a large file, because nothing is recompressed.
One caveat: video is compressed around "keyframes" (roughly one every few seconds), and without re-encoding the start moves back to the previous keyframe — usually by 1–2 seconds (the tool tells you by how much), and the last frame or two may be left out. If you need a frame-exact cut, tick "Frame-accurate": the file gets recompressed once, but the cut lands exactly where you put it.
How to trim
- Open the trim tool — the file stays on your device, nothing gets uploaded.
- Set the start and the end: seconds like "12.5" or timestamps like "1:23" both work.
- Press "Trim video" and download the result.
Frequently asked questions
Why is it so fast? Because without re-encoding the computer does not recompute millions of pixels — it copies ready-made data. Trimming a five-minute clip takes seconds.
Is there a size limit? The source can be several gigabytes — it is never uploaded and is read in chunks. The finished fragment, however, is assembled whole in memory, and such a file cannot exceed 4 GB: if you need a piece that large, cut it in parts.
What if I need to join several pieces? Trim each fragment, then combine them with the merge tool — or assemble the whole thing in the editor with a timeline, transitions and text.