How do I upscale a low resolution image?
To upscale a small photo, upload it to FixDoks's AI Image Upscaler and choose 2x or 4x. The Real-ESRGAN model runs in your browser and adds sharper edges and cleaner detail than normal resizing, without sending the image anywhere. Compare the detail crops, then download the enlarged JPG or PNG.
AI Image Upscaler at a glance
| Model | Real-ESRGAN (x4v3) |
|---|---|
| Scale | 2x or 4x |
| Max input | About 1 megapixel |
| Processing | In your browser; your files are not uploaded |
| Price | Free, no watermark |
| Download | Free Google sign-in |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use AI Image Upscaler
- Select or drop a JPG, PNG or WebP image.
- Choose 2x or 4x enlargement.
- Click Upscale image. The progress bar shows how long is left.
- Compare the detail crops, then download the enlarged image.
How does AI upscaling differ from normal resizing?
When you enlarge a photo in a normal editor, the software invents the new pixels by averaging the ones next to them. The result is bigger but soft and blurry. An AI upscaler has learned from many pairs of low and high resolution images what real edges, textures and fine lines look like, so it can draw sharper edges and cleaner detail at the larger size.
FixDoks uses Real-ESRGAN (the realesr-general-x4v3 model), an open source super resolution network designed for real-world photos. It also reduces JPEG blockiness and mild noise while enlarging.
2x or 4x?
- 2x doubles the width and height (four times the pixels). It is a good choice for photos that are a bit small for printing or for a website.
- 4x makes the image four times wider and taller (sixteen times the pixels). Use it for thumbnails, old small photos, icons and screenshots.
Size limits and speed
The AI runs on your own device, so the work depends on your computer or phone. Images are processed in small tiles to keep memory use low, and a progress bar with an estimated time is shown. To keep things practical, images larger than about 1 megapixel (for example 1000 x 1000 pixels) are reduced to that size before upscaling, which still gives up to 4000 x 4000 pixels at 4x. On a laptop processor a 1 megapixel image usually takes one to a few minutes; smaller images are much quicker. Browsers with WebGPU (recent Chrome and Edge) can use the graphics card and are faster.
What upscaling can and cannot do
AI upscaling makes edges crisper and textures cleaner, and it is very good at removing the blocky look of heavily compressed images. It cannot recover information that is not in the photo at all. A face that is only a few pixels wide will not become a recognisable portrait, and small text that is unreadable will usually stay unreadable. The model can sometimes make skin or grass look slightly painted. Use the detail comparison to judge the result.
Good uses
- Old family photos scanned at low resolution.
- Product images from a supplier that are too small for your shop.
- Logos and icons where you lost the original large file.
- Screenshots and frames from videos.
- Images that need more pixels to meet a minimum size on a form or marketplace.
PNG or JPG output
PNG keeps every pixel exactly and preserves transparency, but files are large. JPG is much smaller and fine for photos you will share or upload. If your image has a transparent background, choose PNG to keep it.