Images can be adjusted by modifying their brightness, contrast, tint, and gamma level[14] manually or automatically, and by converting them between file formats.

[15] A plugin allows IrfanView to support lossless JPG operations: horizontal or vertical flip, rotation by 90° increments, and cropping.

[16][17] IrfanView uses plugins to handle several additional images, video, and sound formats and to add optional functionality such as filter processing or other program features.

[1] Irfanview has been positively reviewed as "really good" for easily and rapidly viewing and manipulating images, with its editing and drawing tools.

In a 2006 interview, then 32-year-old Škiljan said that he was able to more or less live off the software, generating income with the sale of licenses for commercial users and of special versions for different customers.