ResizePixel - Free image editor to crop, resize, flip, rotate and convert images online
Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
Bulk Resize Photos - Resize large photos in bulk
GIMP - GIMP is a multiplatform photo manipulation tool.
PQINA Photo Editor - A free, fast, mobile-friendly, online photo editor to quickly edit pictures.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.