An image forming apparatus includes a storage portion, a preview image generating circuit, an output image generating circuit, a data information obtaining circuit, and a display circuit. The storage portion stores image data that is an output target. The preview image generating circuit generates a preview image from the image data based on an output setting. The output image generating circuit generates an output image from the image data based on the output setting. The data information obtaining circuit obtains data information from output image data of the output image, and discards the output image data from which the data information was obtained. The display circuit displays the data information together with the preview image.