Resize Images Online

What is an image file size?

Images are composed by several dots called pixels, and each of them has a color, represented as a combination of three basic colors (red, green and blue). To store each of these pixels, 3 bytes (24 ones or zeros) are generally used. When an image is large, it may have millions of pixels, and that means storing all information for an image like that in a computer or any device will take millions of bytes.