If you're looking for another Bigjpg alternative, Let's Enhance is worth a look. It's a service that uses AI to enhance and generate imagery, including upscaling low-resolution or blurry images to 4K and beyond. The service offers batch processing, HDR filters and background removal, and is geared for creative professionals and businesses. It also offers APIs for integration into other tools and services, like print-on-demand and e-commerce.
Another option is VanceAI, which offers a variety of tools for photo enhancement, including upscaling, sharpening and denoising. VanceAI offers batch processing and offline processing, which is useful for large-scale image processing. It has flexible pricing and no watermark on output images, so it's geared for professionals.
If you're specifically looking for a high-resolution image restoration service, Remini is a good option. It can upscale photos and videos up to 2x without losing quality and offers options for face enhancement, noise reduction and background detail. Remini is available through a simple API and can be used on mobile devices, so it's good for a variety of situations like social media and e-commerce.
Last, Smart Image Upscaler offers an online tool to upscale images up to 400% without losing quality. It can be used in batch mode and has separate models for different image types. It's particularly useful for anime and cartoon image upscaling, and offers different paid plans depending on your needs.