Double the resolution of a small picture.

Drop in a PNG, JPEG or WebP no larger than 1000×1000 pixels. It comes back at twice the size, resampled and sharpened.

1 free upscale left today.

A 48 by 48 pixel image, enlarged so the individual pixels are visible — A 48×48 source, shown at 4×. The blocks on the left are the original pixels.

The same image after upscaling — A 48×48 source, shown at 4×. The blocks on the left are the original pixels.

What it actually does

Lanczos resampling

Each output pixel is a weighted average of the source pixels around it, using a windowed sinc kernel. It keeps edges from turning into stair-steps the way nearest-neighbour does.

A light unsharp pass

Resampling softens an image slightly. A small unsharp mask afterwards puts the local contrast back without carving halos around high-contrast edges.

Metadata stripped

EXIF, GPS tags and colour profiles are removed on the way through. The file you get back carries pixels and nothing else.

One queue, one worker

Jobs run one after another, so a busy minute means a wait rather than a failure. Your position in the queue is shown while you wait.