Image Enlarger

How does image enlargement work?

Raster images (like JPEGs and PNGs) are collections of individual pixels. When you make an image larger, you are spreading those pixels farther apart. The computer has to decide how to fill in the gaps between the original pixels. This process is called interpolation.

We offer three primary interpolation options:

• Nearest Neighbor: This method finds the nearest pixel in the original image and copies its color directly. It does not mix colors or smooth things out. The result is a sharp, pixelated, retro-looking image. It is perfect for pixel art, screenshots of UI code, or preserving crisp lines.
• Bilinear Interpolation: This averages the colors of the nearest 2x2 grid of pixels. It softens the image and helps get rid of pixel blocks, though it can look slightly blurry.
• Bicubic Interpolation: The gold standard for photo resizing. It calculates a weighted average of a 4x4 grid of surrounding pixels, applying a cubic mathematical curve to create smooth, natural transitions and preserve edges.

Why use our offline client-side upscaler?

Unlike cloud-based upscalers that send your files to remote servers (where they might get saved or looked at), this tool is completely local. Everything happens inside your browser tab using the canvas graphics processor.

For normal resizing, our tool uses high-quality hardware-accelerated rendering pipelines native to modern browsers. For users who need maximum mathematical precision, we also provide a custom bicubic shader implemented directly in JavaScript that calculates the Hermite curves pixel by pixel.