gThumb offers a certain range of image editing operations suited for digital photographs, such as the change of image hue, saturation, lightness, contrast or the adjustment of colors. It can also crop, scale and rotate images by 90° or custom angles and it features a red-eye removal functionality. Manipulated images can be saved in the formats JPEG, PNG, TIFF and TGA.
gThumb can export web-based albums with various theme templates. These albums can be uploaded to a website, providing a very simple mechanism for publishing collections of photos on the web.
gThumb also includes many basic features essential to any image viewer such as copying, moving, deleting or duplicating images, printing, zooming, format conversion, and batch renaming.
The first public version was 0.2 in 2001. Starting from version 2.12.0 gThumb allows you to export photos to various websites. Version 3.0.0 is based on GTK+ version 3, and supports high quality SVG zoom.[clarification needed]
The project's web site on sourceforge.net host a web page listing the history of the software.