Photoshop and GIMP—the open-source Photoshop alternative—may be filled with bells and whistles, but all those tools just add to the software's complexity. Heck, most people don't even need the basics found in Microsoft's own Paint. That's where the lightweight IrfanView comes in.
Irfanview stays lean and mean to focus on lightning-fast file editing and opening times. Converting big batches of image files to new formats is a breeze with this speedy program, and IrfanView still packs everyday editing tools like resizing, rotating, and filtering options. I have Paint, GIMP, and Paint.net on my PC, but IrfanView is the image editor that gets me through my days.