Xandr is an advertising technology company that provides a programmatic advertising platform for buying and selling digital ad inventory across channels. It was created by AT&T through the acquisition of AppNexus and later acquired by Microsoft, where its technology has been integrated into Microsoft Advertising.
Xandr applies machine learning to optimize programmatic bidding, audience targeting, forecasting, and yield management across its demand- and supply-side platforms. Under Microsoft ownership, its capabilities have been positioned to strengthen Microsoft Advertising’s end-to-end programmatic stack.