How it works
A small model runs over every frame on your graphics card and doubles its resolution. That is the whole mechanism.
What happens to your file
- Your file Read from your disk: a video or an image.
- Decoded in the tab The browser turns it into frames, one at a time.
- The model, on your graphics card Each frame comes out at double the resolution.
- Encoded The frames become a video again, or the image is saved as a file.
- Saved where you choose Straight to your disk.
All of this happens on your computer. Your file is never uploaded.
In and out
Video in any shape, at least 720 pixels on the short edge, up to 10 minutes. Out: the same clip at double the resolution, orientation kept. This site does the first 60 seconds; the extension does the rest.
Standard AAC audio at 44.1 or 48 kHz is copied across untouched. Other audio cannot be kept, so the choice is that track or silence.
Images go through too, at exactly double the size, with no minimum. The maximum is whatever your graphics card allows, and the refusal tells you if yours cannot. Nothing has been measured about stills, so the screen shows both versions at actual pixels and you decide.
In the extension, work is saved to disk every two seconds, so a crash costs at most that. A resumed export is valid but not byte-identical to an uninterrupted one. Chrome can refuse persistent storage; when it does, the app says so, and running low on disk could lose work already done.
Three things nobody has settled
It over-sharpens the mid-tones
On video, by 8–10%. That was measured, never resolved, and not investigated. It can read as a synthetic crispness on skin and gradients at full size on a big display.
Every frame is handled alone
The model sees one frame at a time. Whether fine texture flickers between frames has not been measured.
Nothing has been run on a still
Quality was measured on video only, never on a still or on anything under 720 pixels on the short edge.
Check it yourself
For the technically minded
The model runs on WebGPU, in the browser, with no CPU fallback. It needs hardware acceleration switched on and a GPU with f16 support; acceleration being off is the commonest failure. Firefox is untested and expected to fail.
SDR BT.709 on output; HDR input is out of scope.
Weights derived from 2xNomosUni_compact_multijpg by Philip Hofmann (Phips), CC BY 4.0 (creativecommons.org/licenses/by/4.0).