4k → 1080p → 720p
Drop the resolution and watch the size follow
Reducing dimensions removes data before compression is even considered, which makes it the most effective size reduction available. Going from 4K to 1080p discards three quarters of the pixels.
Processed on your own hardware · never transmitted, never stored
What happens when you drop a file in
The file stays put. Your browser opens it the same way an image viewer would. There is no transfer, which is why there is no upload bar to watch.
An encoder arrives once. The first job on this site pulls down a compiled build of FFmpeg, roughly 30 MB. It is kept afterwards, so every job after the first starts immediately.
Your own hardware does the job. The work happens in this tab, on your processor. A laptop from the last few years handles short clips in well under real time.
The result lands in Downloads. Assembled in memory and handed straight to your browser. Close the tab and every trace of it is gone.
Fewer pixels beats harder compression
A 4K frame carries four times the pixels of a 1080p one. Moving down therefore removes three quarters of the picture information up front, which is a far larger saving than any quality slider can deliver.
It also costs less than people expect visually. On a phone, and on most laptop screens, 4K and 1080p are close to indistinguishable — the additional resolution only becomes apparent on a large display viewed from fairly close.
Proportions are preserved automatically. A 16:9 source becomes 1920 by 1080; an unusual shape keeps its ratio with the second dimension calculated to match.
There is deliberately no upscaling here
Enlarging cannot create detail that was never recorded. Tools promising otherwise are either interpolating, which produces a soft waxy look, or running models far too heavy for a browser tab to host. If the delivery needs 4K, the recording needed to be 4K — that decision was made at the camera and cannot be revisited afterwards.
Common questions
Will 1080p look bad after 4K?
On a phone or laptop, no. On a large television viewed closely you may notice slightly less fine detail.
How much smaller does the file get?
Typically sixty to seventy five percent going from 4K to 1080p, depending on content.
Can I go the other way?
No, and no tool can do it honestly. Resolution cannot be invented after the fact.
Does the file get uploaded?
No, the work happens on your machine.