nomacs is described as 'Free, open source image viewer, which supports multiple platforms. You can use it for viewing all common image formats including RAW and psd images' and is a very popular Image Viewer in the photos & graphics category. There are more than 100 alternatives to nomacs for a variety of platforms, including Windows, Linux, Mac, Flathub and Xfce apps. The best nomacs alternative is IrfanView. It's not free, so if you're looking for a free alternative, you could try IrfanView or XnView MP. Other great apps like nomacs are FastStone Image Viewer, qView, XnView Classic and Gwenview.
Plug in your memory cards and start picking winners and deleting rejects almost instantaneously. Move from image to image without that annoying rendering delay. Add dynamic caption, copyright, and keyword information individually or in batches.
PhotoQt is a fast and simple, good looking, yet powerful and highly configurable image viewer.
Germany
EU
Lathe is a fast, privacy-first media manager for macOS. Browse, organize, and batch-process your photos, videos, and PDFs, entirely on your Mac.
A no-nonsense hardware-accelerated image viewer. Oculante's vision is to be a fast, unobtrusive, portable image viewer with wide image format support, offering image analysis and basic editing tools.
Pixyway is a fresh new picture viewer for Windows. It has been designed to be an 'everyday' picture viewer tool like Google Picasa viewer used to be! By the way, if you liked Picasa viewer, you will notice some references to it.
NX Studio is a computer software that allows users to enjoy the viewing, processing, and editing of still images and video, and provides more intuitive operation.
Japan
feh is an X11 image viewer aimed mostly at console users. Unlike most other viewers, it does not have a fancy GUI, but simply displays images. It is controlled via commandline arguments and configurable key/mouse actions.
GermanyEU
Universal Viewer is an advanced file viewer for wide range of formats. Supported file formats are:
Russia
Geeqie is a free open software image viewer and organiser program for Linux, FreeBSD and other Unix-like operating systems.
CzechiaEU
View directly, image pinning, diverse formats, and EXIF information. Optimized for viewing long images, the perfect mac platform image viewer.
QuickViewer is a graphic image viewer for comfortable browsing of many images. This software performs reading of image data in advance. And drawing the imported image data on the screen with OpenGL. You can browse images with much smoother response than ever before.
Japan
Image viewer offering support for HDR, RAW, extensive formats, webtoon mode for comics, fast navigation, batch conversion, slideshow, detail zoom, drag-and-drop, efficient browsing, keyboard shortcuts, multi-monitor support, and portable usage options.
South Korea
United States
