FastStone Image Viewer vs ImageGlass

FastStone Image Viewer is a Windows image browser, converter, and editor for individual images and collections. Editing tools include resizing, rotation, cropping, color adjustment, sharpening, blur, Clone Stamp, and Healing Brush. It supports major graphic formats and popular camera RAW formats, including HEIC, WEBP, PDF, SVG, and JPEG XL. The Compare Images feature displays up to four pictures side by side, while batch tools convert and rename collections. Slideshows offer more than 150 transition effects and music. The program can acquire images from scanners and batch scan to PDF, TIFF, JPEG, or PNG. Users can launch external editors from within Image Viewer, and a portable version can run from removable storage. FastStone lists personal and educational use as free and a commercial lifetime license at $34.95 as a one-time purchase, with upgrades free. Another plan listing gives a price of $34.95 a month, so the commercial license terms should be confirmed before purchase. The product is listed for Windows, and FastStone provides technical support by email.

ImageGlass is a desktop image viewer for browsing and viewing image files on Windows, macOS, and Linux. It supports more than 90 formats, including WEBP, GIF, SVG, PNG, JXL, HEIC, and RAW. Viewing tools include slideshows, thumbnails, color picking, hardware-accelerated rendering, and EXIF information through ExifGlass. Built-in edits cover rotation, flipping, cropping, lossless compression, and resizing. Pro adds an HDR Tone Mapper, free and margin panning, File Watcher, custom mouse clicks, and settings and feature locks. The app can associate external editing apps, use custom hotkeys with them, and accept extensions built with its SDK. ImageGlass says it does not scan image libraries for analytics or send images, filenames, or folder paths elsewhere. Classic is free. Pro Individual is $14.90, paid once purchase; Pro Team is $69, paid once purchase. Pro Business is $9,917 a year. The 14-day Business trial requires no account, online activation, or device lock for local license verification.