Sharpen a Blurry Photo — Pro, on our server
Sharpness is two different things wearing one word. Resolution is how much detail the file physically contains; acutance is how abruptly brightness changes at the edge of that detail. A sharpen slider only raises acutance — it darkens the dark side of every edge and brightens the bright side so your eye reads the transition as crisper. The photograph gains no information at all, which is why a heavily sharpened image can look simultaneously crunchy and empty. The Cloud HD enhancer works on the resolution side instead: it predicts the fine structure that would have produced these soft pixels and paints it back in, blended with your own data.
Halos are permanent, so sharpen last or not at all. Radius and amount are the two knobs on an unsharp mask, and a radius wider than a couple of pixels leaves a visible light rim on every high-contrast boundary — bare branches against sky are the classic giveaway. Save that as a JPEG and the halo is now part of the image data; a later model reads it as genuine light and reconstructs around it, which is how a photo ends up looking retouched by two people who never spoke. If you have a haloed copy and an unsharpened one, upload the unsharpened one.
Know whether sharpening is even the right answer. If the image is soft because your hands moved, the honest frame is motion, and unblurring a shaky image explains what survives. If it is soft because the focus landed on the wrong plane, that is a different failure again. If you are not sure which of the causes applies, the triage page on fixing a blurry photo walks through telling them apart before you spend anything. Sharpening is the right word only when the detail is present but low in contrast.
The privacy position, without the usual overstatement. Nearly every MiniPx tool — the compressors, the converters, the croppers — runs entirely inside your browser and uploads nothing. Cloud HD is the deliberate exception, because RestoreFormer++ will not fit in a tab: the photo is uploaded to our server for that run and deleted when the run finishes, and in all cases within 24 hours, processed in the United States, encrypted in transit, and never used to train anything. When you want a smaller file for the web after sharpening, the on-device compressor does that with no upload at all.