FastStone Image Viewer

FastStone Image Viewer is an image viewer and organizer software for Microsoft Windows, provided free of charge for personal and educational use. The program also includes basic image editing tools, like cropping, color adjustment and red-eye removal.
Developed by FastStone, it was first released in 2004 and new stable versions have been released regularly since. It is available as an executable installer, zip, and a portable zip version.

WWW Official Site

Features

Thumbnail viewer
Crop Board and Draw Board
Resizing, cropping, color correction, red-eye removal, clone brush, curve (tonality), levels, and unsharp mask
Side-by-side image comparison
Resampling
Magnifier lens
Batch operations including rename and convert
Color space management
Slide show, including music and transition effects
Memory card image retriever
Displays Exif camera metadata
Support for BMP, JPEG, JPEG 2000, animated GIF, PNG, PCX, TIFF, WMF, ICO, and TGA - including raw formats like Canon's CR2 or Sony's ARW

Reception

Upon release, the software site SnapFiles rated it five stars out of five. It also received five stars by the editor of Download.com. A PCWorld magazine review of version 4.0 of FastStone Image Viewer in 2011 noted the software's "lightning-fast" display of pictures. The reviewer felt that one of its greatest advantages was its "wide variety of file formats" the software supports. Rick Broida of CNET wrote in 2015 about version 5.4: "This freeware gem remains an essential download for anyone looking to view, edit and organize their photos." Broida thought that it was a "bit more robust" compared to IrfanView.