They're using established open source models and code, just under their own web UI. Specifically Real-ESRGAN for the upscaling, and Codeformer for the face enh

They're using established open source models and code, just under their own web UI. Specifically Real-ESRGAN for the upscaling, and Codeformer for the face enhancements, which is what most people are doing. Though my company is using GFPGAN for the facial enhancements at the moment. "AI Image Enhancement" websites are all using the same stuff.