An image viewer or image browser is a computer program that can displays stored graphical image; it can often handle various graphics file formats. Such software typically renders the image according to properties of the display such as color depth and display resolution.

Although one may use a full-featured bitmap graphics editors (such as Photoshop or the GIMP) as an image viewer, these have many editing functionality which is not needed for just viewing images, and therefore typically start rather slowly. Also, most viewers have functionalities that editors typically lack, such as stepping through all the images in a directory (possibly as a slideshow).

Image viewers give maximal flexibility to the user by providing a direct view of the directory structure available on a hard disk. Most image viewers do not provide any kind of automatic organization of pictures and therefore the burden remains on the user to create and maintain their folder structure (using the tag or folder based methods). However, some image viewers also have features for organizing images, particularly an image database, and hence can also be used as an image organizer.

Typical features of image viewers are:

basic viewing operations such as zooming and rotation

fullscreen display

slideshow

thumbnail display

printing

screen capture

Advanced features are:

decode next image in advance and keep previous decoded image in memory for fast image changes

display (and edit) metadata such as IPTC and Exif

batch conversion (image format, image dimensions, etc.) and renaming

create contact sheets

create HTML thumbnail pages

different transition effects for slideshows

Common image viewers include:Windows

Windows Explorer - file manager with basic built-in functionality for image viewing

Windows Picture and Fax Viewer

ACDSee, XnView, IrfanView, FastStone Image ViewerUNIX-like

xv, Kuickshow, GThumb (Linux)