How to upscale an image without blur
Every enlargement has to invent pixels that were never there. Stretch a 200 pixel logo to 800 and three out of every four pixels in the result are guesses. How those guesses get made is the whole difference between a soft, smeary enlargement and a sharp one.
Why a stretched image goes soft
When a browser or a basic editor enlarges an image, it fills each new pixel with a blend of the two or four original pixels nearest to it. That's quick, and it never produces anything strange, but blending is exactly what blur is. Every hard edge in the original becomes a short gradient, and the bigger the enlargement, the wider that gradient gets.
Nothing about that is fixable after the fact by sharpening. Sharpening boosts the contrast of edges that are already there. It can't put back a crisp outline that the stretch has smeared across four pixels.
The two better ways to do it
Lanczos3 is a smarter blend. It weighs six original pixels on each axis instead of two, using a curve that favours keeping edges steep, so outlines stay noticeably crisper than a plain stretch. It still only uses what the image contains, which makes it the safe, predictable choice for photos.
An AI upscaler works differently. Real-ESRGAN, the model this site uses, was trained on millions of image pairs to redraw a sharp version of what it sees. Given a blurry letter or a soft logo outline, it draws a clean one. That's a big win on flat graphics and text, and the reason it's the wrong tool for faces and fabric: it will smooth real texture into something that looks painted.
Which one to use
Photos of people and products: Lanczos3. You want what the camera captured, only larger, not a model's idea of what skin should look like.
Logos, icons, diagrams, screenshots, cartoons, pixel art and anything with small text: AI. These are made of flat colour and hard edges, which is exactly what the model is good at rebuilding.
Pick 2× for screens and the web, 4× when the result is going to print or you need to crop in. The bigger the jump, the more the tool is filling in, whichever method you choose.
How to upscale an image in your browser
Open the image upscaler, choose a method and a factor, and drop your image. The enlarged file comes back ready to download, as JPG, PNG or WebP.
The AI method runs on your graphics card through WebGPU, which current versions of Chrome and Edge support. The first time you use it, the browser downloads the model and its runtime, about 36 MB, and keeps them, so the next image starts straight away. If WebGPU isn't available, the tool tells you and uses Lanczos3 instead. AI takes images up to 1 megapixel, around 1000 by 1000 pixels.
Upscaling a logo before turning it into a vector
If the goal is a scalable logo, an enlargement is often the wrong end point. The image to SVG converter traces the logo into shapes that stay sharp at any size, and it has the same AI step built in: small images up to 512 pixels are redrawn at four times the size first, so the tracer has real edges to follow instead of a few blurred pixels.
What no upscaler can do
An upscaler can't recover detail the original never recorded. A face that's ten pixels wide in a group photo will come back as a plausible face, not that person's face. Tiny text the camera couldn't resolve comes back as tidy shapes that may not be the right letters. For anything where accuracy matters, like a number plate or a document, treat the enlargement as a clearer picture, not as evidence.
Quick questions
Should I use AI or Lanczos3 to upscale a photo?
Lanczos3. It enlarges what the camera recorded without inventing texture. AI suits logos, drawings, screenshots and text, and can make photos look painted.
Why does my enlarged image look blurry?
A basic stretch fills new pixels by blending the ones next to them, and blending softens every edge. Lanczos3 keeps edges crisper, and AI redraws them.
Is my image uploaded to be upscaled?
No. Both methods run in your browser, and the AI one runs on your own graphics card. Nothing leaves your device.
Why is the AI option unavailable in my browser?
It needs WebGPU, which current Chrome and Edge support. Without it the tool uses Lanczos3 and tells you so.
How much does the AI method download?
About 36 MB the first time you use it. After that the browser keeps it, so it works offline and starts instantly.
Can AI upscaling recover a blurry face or number plate?
No. It can draw something sharp and plausible, but not detail the photo never captured. Don't rely on it where accuracy matters.
What is the largest image I can upscale with AI?
Up to 1 megapixel, about 1000 by 1000 pixels. Larger images are enlarged with Lanczos3 instead.
Converters
The converter on this page handles every conversion this guide talks about.