How to Upscale an Image (Free, and Private)

Step by step

1. Open the toolGo to the Image Upscaler — it runs in your browser, with no install or account.
2. Add your imageDrop in a JPG, PNG, or WebP. It works best on smaller images (up to about 1200×1000 pixels).
3. Choose 2× or 4×Pick 4× for maximum detail on very small images, or 2× for a sharper result at a smaller, more shareable file size. The tool shows the exact output dimensions before you start.
4. Upscale and downloadClick Upscale image, watch the progress, then download the enlarged PNG. Your image never leaves your device.

How it stays private

The AI model runs locally in your browser and is served only from Kitolity’s own servers — your image is never uploaded and nothing is stored. A small (~4.7 MB) model downloads once on first use and is then cached, so every image after the first upscales without any further download.

Why AI upscaling beats a plain resize

When you enlarge an image the ordinary way, the software just stretches the pixels it already has, so edges turn soft and fine detail smears — the picture gets bigger but not clearer. An AI super-resolution model works differently: it has learned what real edges, textures, and shapes look like, so as it enlarges it reconstructs plausible detail, giving crisper lines and cleaner text than interpolation ever could.

This tool uses Real-ESRGAN, a widely used open super-resolution model, running fully on your device via WebAssembly. It processes the image in overlapping tiles so pictures of different sizes fit in memory and the enlarged result stays seamless, with no visible grid.

2× vs 4× — which to choose

The model natively quadruples each side (4×), which recovers the most detail and is ideal for very small images, icons, and old thumbnails. Choosing 2× runs that same 4× model and then does one high-quality step down to double the size — you still get the AI-reconstructed detail, but at a smaller, more practical file that’s easier to share or upload.

As a rule of thumb: use 4× when the source is tiny and you need every bit of size you can get, and 2× when you want a noticeably sharper image without a very large output.

What upscaling can and can’t do

Upscaling shines when an image is simply small — a low-resolution logo, a compressed thumbnail, a tiny profile picture, or a product shot that needs to print larger. In those cases it can make a dramatic difference.

What no upscaler can do is invent detail that was never captured. A photo that’s heavily blurred, badly out of focus, or crushed by heavy compression has lost information the model can only guess at, so those improve less than an image that’s merely small. For the best result, start from the sharpest, least-compressed version of the image you have.