OpenRTB is the open protocol that lets buyers and sellers trade digital ad impressions through real time bidding. It defines the common language, objects, and rules that make programmatic auctions possible at web scale. When an impression becomes available, an exchange uses OpenRTB to describe it to many buyers, collects bids in milliseconds, and returns the winning creative to the publisher.
OpenRTB is a shared specification that standardizes how supply side platforms and demand side platforms exchange bid requests and bid responses. The goal is simple. Interoperability, consistency, and speed for programmatic advertising across display, video, native, audio, in app, mobile web, and connected TV.
OpenRTB messages are typically JSON. The request describes the user, device, app or site, ad slot, allowed formats, regulations, and privacy flags. The response contains the bid price, the creative or ad markup, tracking beacons, and deal terms. With one protocol in place, platforms integrate faster and maintain fewer custom connections.
| Role | Who uses it | Primary job | Key actions |
|---|---|---|---|
| SSP, supply side platform | Publisher or app developer | Package and sell inventory | Create bid requests, set floors and rules, run auctions, enforce policies |
| DSP, demand side platform | Advertiser or agency | Buy inventory that fits goals | Evaluate requests, apply targeting and pacing, bid and return creatives, report outcomes |
SSPs and DSPs rely on OpenRTB so one integration can reach many partners with consistent fields and behavior.
Many markets have moved to first price with transparent floors and deal terms. OpenRTB supports both.
Speed and scale
Billions of opportunities can be priced in milliseconds because every system speaks the same protocol.
Lower integration cost
Fewer custom adapters and faster onboarding of new partners.
Richer context for better ads
Standard objects carry placement, app or site, device, content, and regulatory information that improves targeting and brand safety.
Market transparency
Companion standards such as sellers.json and supply chain objects help buyers verify who is selling what.
The spec evolves, yet the mission remains the same. A clear, shared language for programmatic trade.
Validate every message
Enforce schemas, required fields, and value ranges. Log reasons for bid filtering to speed partner debugging.
Honor privacy and policy signals
Respect consent strings, Limit Ad Tracking flags, and regional regulations. Pass and enforce them consistently.
Defend against fraud
Use supply chain objects, sellers.json, ads.txt or app ads.txt, device integrity checks, and anomaly detection for traffic quality.
Price with intention
Set rational floors, monitor win rates, and align first price strategies with your demand mix. Test deals and preferred access for premium supply.
Measure outcomes, not only bids
Optimize to viewability, attention, and business conversion where possible. Share feedback loops with partners.
A shared protocol that lets ad platforms buy and sell impressions by real time auction.
RTB is the auction method. OpenRTB is the language those auctions use to communicate.
SSPs, DSPs, exchanges, and any vendor that intermediates bids or creatives at scale.
Yes. Current versions include fields for streaming video, pods, app level identifiers, and device specifics.
Most markets prefer first price for clarity. You can still run second price if your marketplace and partners support it.
Through standardized authentication artifacts such as supply chain objects, sellers.json, and signed signals, plus room for vendors to add verification and scoring.