120x600

120x600 refers to a digital advertising banner size consisting of an image or creative 120 pixels wide and 600 pixels tall. It is commonly known as a skyscraper ad and is used primarily in desktop website layouts. The tall, slender format makes it well-suited for brand messages and repeated exposure as users scroll down a page; placements are typically in the left or right sidebar, sometimes near the content fold.

Creatives come in static (GIF, JPG, PNG) or animated (GIF) formats, and increasingly as HTML5 or rich media in some campaigns. Ad networks and exchanges usually impose file-size and encoding requirements, and designers optimize to meet those constraints while preserving legibility on various devices.

Historically popular in early online advertising, the 120x600 remains in use but is less common on mobile devices and in responsive or fluid layouts. Some sites replace fixed banners with adaptive units or remove fixed-height ad slots to improve user experience.

Due to its fixed height, the 120x600 can have good visibility on large screens but may be blocked by ad blockers; campaigns using this size should consider accessibility and alt text for screen readers.

See also: IAB banner ad sizes, digital advertising, skyscraper ad.