Advanced TV & Digital
OpenRTB (Real-Time Bidding)
A standard technical protocol for the automated, auction-based buying and selling of ad impressions within milliseconds.
What is OpenRTB (Real-Time Bidding)?
OpenRTB is the protocol maintained by the IAB that defines how DSPs and SSPs communicate during programmatic auctions. When an impression becomes available, the SSP sends a bid request — specifying the user, context, format, and constraints — to every connected DSP; each DSP evaluates the opportunity against its bidding rules and returns a bid; the highest qualifying bid wins; the ad is served. Every step completes in roughly 100–300 milliseconds.
OpenRTB standardisation is why programmatic scaled. Before OpenRTB, every DSP-to-SSP integration required bespoke engineering. With the standardised protocol, any compliant DSP can buy from any compliant SSP without custom work, which collapsed the cost of programmatic expansion and made global-scale ad exchanges practical. The protocol has evolved through multiple versions (2.x, 3.x) and now covers CTV, audio, and digital-out-of-home as well as traditional display.
Why it matters
OpenRTB acts as the universal language enabling programmatic ecosystems to function smoothly across diverse ad exchanges and networks globally.
Related terms
- Programmatic TV / Audio— The automated, machine-to-machine buying and selling of broadcast ad inventory through complex algorithms and real-time bidding systems.
- ACR (Automatic Content Recognition)— Technology embedded within Smart TVs that visually or acoustically scans what is playing to identify the exact content or commercials.
- CTV (Connected TV)— Televisions connected to the internet via internal smart capabilities or external devices (e.
- DSP (Demand-Side Platform)— A software system utilized by advertisers and agencies to automate the purchase of programmatic digital, audio, and video inventory.