How to check that nothing is uploaded
Open your browser's developer tools, switch to the Network tab, then drop an image. The only requests you will see are the one-time download of the 5 MB model and the runtime files, both from this site, plus a cookieless page-view ping. No request carries your image, and none is sent to a third party.
A second test needs no tools at all: load this page, turn Wi-Fi off, then upscale. It still works, because the whole pipeline is already on your device.
Why most upscalers upload, and why this one does not
Cloud upscalers send your image to a server farm, run the model there, and send the result back. That is why they need accounts, credits and a privacy policy that promises to delete your files "within 24 to 72 hours". Running the same model in the browser removes the upload, and with it the account, the quota and the retention question.
The trade-off is that your own hardware does the work. On a recent laptop with WebGPU a 1-megapixel photo takes a few seconds; on the WebAssembly fallback it is about 6× slower. Phones work too, with a 2-megapixel input limit so the 4× result fits in memory.
What you get
A lossless PNG at 4× the original width and height: 800×600 becomes 3200×2400. No watermark, no compression, no account, no limit on how many images you process.
Questions, answered
Is the image really never uploaded?
Correct. There is no upload endpoint on this site. Inference runs in a Web Worker in your browser, and you can confirm it in the Network tab or by upscaling with Wi-Fi turned off after the page has loaded.
Does anything about my image get logged?
No. The only analytics is a cookieless page-view count plus coarse funnel events (which engine ran, a size band, a duration band). Nothing derived from the pixels, no filenames, no dimensions.
Can I use it for sensitive photos, IDs, or medical images?
Nothing leaves your device, so the privacy risk is the same as opening the file locally. Keep in mind the model is a general-purpose photo enhancer; it does not include a dedicated face-restoration pass and it is not a diagnostic tool.
Curious what "AI upscaling" actually does? Read the plain-English guide, or go back to the upscaler.