OpenX

One of the largest independent programmatic ad exchanges globally, competing with Google Ad Manager, Magnite, and PubMatic

OpenX is a global programmatic advertising technology company founded in 2008, headquartered in Pasadena, California. The company operates one of the world's largest independent ad exchanges, providing publishers with a supply-side platform (SSP) and offering buyers access to high-quality programmatic inventory across display, video, mobile, and connected TV (CTV) formats. OpenX is known for its commitment to a clean, fraud-free marketplace and has been a pioneer in initiatives around supply path optimization (SPO) and sustainable advertising. OpenX's core offerings include its ad exchange, publisher monetization tools, and buyer access solutions that enable real-time bidding (RTB) and programmatic direct transactions. The company has invested heavily in identity solutions, contextual targeting, and privacy-safe advertising technologies to adapt to a cookieless future. OpenX has also been recognized for its sustainability efforts, becoming the first carbon-neutral ad tech company. In the competitive AdTech landscape, OpenX positions itself as a premium, independent alternative to walled gardens and large platform-owned exchanges. It serves thousands of publishers and connects with hundreds of demand-side platforms (DSPs) globally, making it a significant player in the open programmatic ecosystem. Its independence from large media conglomerates is a key differentiator, allowing it to maintain neutrality and alignment with both publisher and buyer interests.