ImageKit.io - Instant multi-platform image optimization
PhotoPenguin App - PhotoPenguin is a completely free batch photo editor with support for cropping, resizing, adding watermarks, and converting photos to other formats. It works on the user's device, using the capabilities of modern browsers.
Promo.com - Every promotion starts with Promo.com.
Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats
Pixelhunter.io - Free AI image resizing tool for social media
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.