Zyro

Zyro is a free AI image upscaler which you can access on their website. The tool lets you upscale your images up to 4x and the results I got from my testing were pretty great. Even compared to other GPU-heavy upscalers like ESRGAN the upscaled images looked very similar in quality. Zyro took about 2 minutes to upscale after I input my image, which isn’t too bad considering the tool is free!