If you're looking for a PhotoKit alternative, Snapclear is worth a look. This desktop app runs on Windows, Linux and macOS and includes AI-based image processing, background removal and offline batch processing. Snapclear is designed to protect privacy since all the processing takes place on your machine, so it's a good pick if you have data you need to keep secret.
Another good option is Topaz Labs. It's a collection of professional-grade photo and video editing software that uses deep learning to improve image quality. With tools like Photo AI 3 for sharpening photos and upsizing them and Video AI 5 for stabilizing video, Topaz Labs has some serious horsepower for Mac and Windows machines. It runs locally so your data is private.
For a general-purpose image editing service, check out AILab Tools. It uses AI for tasks like removing backgrounds, changing facial expressions and colorizing photos. It also offers an API interface so you can integrate its image processing abilities into other apps. AILab Tools offers several subscription tiers, including a free option, so it's good for photographers and e-commerce site operators.
Last, HitPaw Online is an all-purpose AI-powered editing service with tools to improve photo, video and audio. The service includes background removal, image watermark removal and video compression. Pricing is flexible, including a free version, so HitPaw Online is good for social media managers, photographers and content creators who need a one-stop editing service.