Windows comes with its image viewing app called Photos. But it is very slow, lacks so many features compared to other third-party image viewers and does not support all the popular image file formats. This is why many Windows users use third-party image viewing software like IrfanView, FastStone or XNView. I personally have been using IrfanView on Windows computers because it is very fast and can open almost all the known image file types out there. It can even open RAW and PSD images.
Now IrfanView has a serious competition in the name of Nomacs – an open-source, cross-platform, and very fast image viewer. Nomacs is available in portable format as well as a setup installer. When you launch Nomacs the very first time, you are given the options to set file associations and making it the default image viewer. Once the file associations are set, you can double-click on any image file to open it in Nomacs.
Nomacs uses very plain native user interface but offers all the necessary functions. You can open an individual image in it or open a directory full of images. In the latter case, it will display a gallery of all the detected images. It makes it very easy for you to select an image from a folder containing thousands of images and it is considerably faster than Windows File Explorer.
Nomacs can be used to do basic editing of the images. It comes with all the important functions of image manipulation. For example, you can adjust the brightness, contrast, saturation, hue, or gamma of an image. You can make it grayscale, invert colors, flip horizontal, flip vertical, rotate, resize and crop the images.
Nomacs’ most powerful feature is synchronization of multiple Nomacs instances. Using this feature (available from Sync menu in the menubar), you can connect two or more instances of Nomacs running on the same computer or across a network. You can sync both the view and the actions. When views are synced all instances have same zoom level – if you change zoom in one instance, it changes in all instances. Similarly, when you sync actions, changes made to the opend image in one instance affects all the instances.
Nomacs is a really fast and powerful image viewer. It supports all the popular image formats, offers basic image manipulation functions and allows synchronization of multiple instances.
You can download Nomacs image viewer from https://nomacs.org/.