Best AI Image Upscaling Tools for Windows

Have you ever wanted to breathe new life into a cherished photo by increasing its resolution? While there are many cloud-based services available to upscale your images, these can raise privacy concerns, as you’re uploading your data to someone else’s server. Fortunately, there’s another option: AI image upscaling with free local tools that run on your Windows machine.

1. Best for Most Windows Users: Upscayl

Easily, my favorite local AI image upscaler for Windows is Upscayl, and there are several reasons why.

First, Upscayl is completely free and offline, meaning you can use it without any hidden costs (even for commercial purposes), while keeping your images entirely on your machine. Second, the tool has a well-designed user interface that makes it easy to use, even for those who are not tech savvy. Third, you can choose from more than 10 upscaling models to achieve the best results, regardless of whether you’re trying to increase the resolution of photos or artwork.

To get started, visit Upscayl’s official website, and download the Windows installer. Open the installer file, follow the installation wizard, then launch the application.

With Upscayl running, drag and drop the image you want to upscale into the application window, and click the Upscayl button. The tool will increase the resolution of your image using a general-purpose upscaling model and save the result in the same folder with the source image.

In my case, the software successfully increased the resolution of a stock photo from 640×427 pixels to 2560×1708 pixels, and the result speaks for itself.

The default settings produce good results in most situations, but sometimes it’s a good idea to select a different model, such as when upscaling digital art. Alternatively, head to the Settings tab, where you can disable post-processing, change the amount of upscaling, pick your preferred output file format, and more.

2. Best for Upscaling Anime Images: BigJPG

Another excellent local AI image upscaler for Windows is BigJPG. This tool uses deep convolutional neural networks to reduce noise and serration in images, allowing them to be enlarged, without losing quality. One of the standout features of BigJPG is its ability to handle anime images and illustrations, which are nearly perfectly processed with well-kept colors, details, and edges. Regular photos are also supported.

You can download BigJPG for Windows from its official website. Extract the downloaded archive, and launch the installer inside. The installation process is straightforward, and the installer wizard will walk you through one step at a time.

The free version of BigJPG allows you to enlarge up to 20 pictures per month, with a maximum enlarging ratio of 4x. This version supports offline enlarging, so you can avoid uploading your images to BigJPG’s China-based servers (where they stay for three days before they are automatically deleted).

As with Upscayl, drag and drop your image into the BigJPG window, and click the Start button. It shouldn’t take long. Then, click the Download button, and save the upscaled image in your desired location.

3. Best for Advanced Users: Portable Real-ESRGAN

Most AI image upscalers rely on the Real-ESRGAN algorithm, which has been trained with synthetic data to significantly improve the visual quality of upscaled images.

Thanks to Portable Real-ESRGAN, you can run the algorithm directly in the Terminal app on Windows with a compatible Intel, AMD, or Nvidia GPU. The tool’s command-line nature opens a world of possibilities for advanced users who want to automate the upscaling process or integrate it with other scripts.

To use Portable Real-ESRGAN, download the executable file from the official GitHub repository, and run it in the Terminal app with the appropriate command-line arguments. For example, the following command upscales an input image by a factor of 4, using the default Real-ESRGAN model, and saves the output in PNG format:

realesrgan-ncnn-vulkan.exe -i input.jpg -o output.png -s 4 -n realesrgan-x4plus

The tool supports various command-line arguments to customize the upscaling process, such as specifying a different model, changing the tile size, or enabling tiling and cropping. You can find a complete list of available arguments in the tool’s documentation section on GitHub.

AI image upscaling is made possible with these Windows tools that enhance your images without sacrificing privacy. If you’re interested in generating AI images rather than just upscaling them, be sure to check out our article on using Stable Diffusion to create AI-generated images.

Image credit: DALL-E. All screenshots by David Morelo.

David Morelo - Staff Writer

David Morelo is a professional content writer in the technology niche, covering everything from consumer products to emerging technologies and their cross-industry application. His interest in technology started at an early age and has only grown stronger over the years.