nomacs is a free, open-source and cross-platform universal image viewer & simple editor from Austria. If you have many photos to view, edit or manage, this software will be a very convenient choice. In addition to the common image formats, it also supports some proprietary image file formats such like RAW and PSD.

nomacs features lightweight file size, fast running speed, and the ability of processing all the common image formats. Plus, it has more special functions worth mentioning: semi-transparent widgets that display additional information such as thumbnails, metadata or histogram; capacity of direct browsing images in a zip or MS Office file; file explorer panel that allows to switch between folders and supports file filters; caching function that can accelerate the switch operation between images; and especially its multi-picture comparing feature that supports the comparison of pictures between multiple computers in the same LAN, which can be very useful in some engineering and designing situations.

In the field of image editing, nomacs is able to adjust the brightness, contrast, saturation, hue, gamma, exposure and other image data. Besides, nomacs also comes with a very unique capability: synchronization of multiple instances. This enables user to easily compare multiple images by zooming, panning or overlaying them with different opacity.

Key Features

Function Features
Image Viewing
  • supports the most common image formats including RAW (see table below)
  • fast thumbnail preview
  • zoomable grid preview of thumbnails
  • display exif information
  • framless view
  • change transparency of windows
  • display overview/histogram/file info
  • file filtering/searching/sorting
  • improved anti-aliasing
  • hide menubar and toolbar
  • slideshow
    • image information (e.g. date created)
    • play/pause with user defined time interval
    • adjustable background color
Image Editing
  • crop images
  • resize images
  • pseudo color function
  • color adjustments (brightness/contrast/saturation …)
  • multi page TIFF export
  • rotate images
  • drag and drop images
  • automatically save screenshots
  • delete/rename images
  • create mosaic image
  • set wallpaper (windows only)
Viewer Synchronization
  • synchronize multiple instances
    • synchronized zooming
    • synchronized panning
    • synchronized next/previous file
    • overlay of two or more instances (with changing opacity)
    • arrange synchronized instances
  • synchronize multiple instances in the LAN
    • synchronized zooming
    • synchronized panning
    • images can be sent over LAN connection

Supported Image Formats

  • jpg
  • png
  • tif
  • bmp
  • ppm
  • xbm
  • xpm
  • jpeg2000
  • webp
  • gif
  • ico
  • pbm
  • pgm
  • nef
  • crw
  • cr2
  • arw
  • mrw
  • rw2
  • dng
  • mpo
  • jps
  • pns
  • psd
  • psb
  • tga

Official Demo Video

Related Links

Download URLs

License Version Download Size
Freeware Latest  (mir) n/a
(Homepage | GitHub)