What this upscaler actually does
This tool enlarges an image using interpolation. When you ask for more pixels, the browser has to decide what color each new pixel should be, and interpolation fills them in by blending the colors of the nearest existing pixels. The result is a larger image with smooth transitions instead of visible blocks.
It is not an AI super-resolution model. It does not recognize faces, text or textures and does not generate new detail. The extra pixels are calculated averages of what was already there, so the picture gets bigger but not sharper in any real sense. A blurry thumbnail becomes a larger blurry image.
To soften the blockiness that a single big jump can cause, the tool enlarges in two steps. It first resizes to an intermediate size (the square root of your chosen factor, applied to the width and height), then resizes again to the final size. For 4x, the intermediate step is 2x, and for 2x it is about 1.41x.
When enlarging by interpolation is enough
Modest enlargements are where this approach works. If a picture is slightly too small for a slot, such as a banner that needs a few more pixels, a document figure, or a profile picture a little under the minimum, a clean 2x enlargement can be acceptable, especially for graphics with flat colors and smooth shapes.
It is also useful when a tool or form demands minimum dimensions and you simply need the file to meet them, or when you want to view small artwork at a larger size on screen.
It is a poor fit when you expect restoration. Heavily compressed, tiny or noisy sources will not turn into crisp, print-ready images. If you need the opposite, a smaller file, use the Image Resizer or the Image Compressor.
How to upscale an image with this tool
- Drag an image onto the upload area or click it to select a file.
- Choose a scale with the 2x, 3x or 4x buttons. The default is 2x.
- Click Upscale. The original appears on the left, and the enlarged version appears on the right once it is ready.
- Click Download to save the result. The file is a PNG named after your original with the factor added, for example "photo-3x.png".
- Use Start over to pick another image.
Everything runs in your browser. The image is not uploaded by this tool. If you change the scale after upscaling, click Upscale again to generate a new version.
Choosing a scale and avoiding surprises
Pick the smallest factor that meets your need. Each increase makes the softness more obvious, and 4x of a small image will look noticeably soft when viewed at full size. As a worked example, an 800 by 600 image becomes 1600 by 1200 at 2x, 2400 by 1800 at 3x, and 3200 by 2400 at 4x.
Output size grows quickly. A 4x enlargement has sixteen times as many pixels as the original, so a large source can create a very large canvas, and some browsers or devices may struggle or fail with extremely big images.
You can compare your before and after with the Image Comparison slider if you want to judge the difference.