First, check AI Image Enlarger, a free online tool that uses AI to increase image sizes up to 800% without losing quality. It's good for just about anyone and works on Windows, Mac, iOS and Android devices, with fast processing and a track record that's been tested by more than 1 million people in 60 countries.
Another top pick is Topaz Labs, a collection of professional-grade photo and video editing software that uses deep learning technology. Its Gigapixel 7 tool increases image sizes up to 600% with AI models. It runs on your computer, Mac or Windows, so you can keep your data private, and it offers batch processing and immediate deployment.
Last, Let's Enhance offers AI-powered image enhancement and generation tools that can increase image size to 4K or more and remove backgrounds. It's geared for creative pros, e-commerce and real estate customers who need to quickly increase image sizes for prints and website use. The service offers a free trial and flexible pricing.