Ads.txt – Authorized Digital Sellers

IAB Tech Lab has now finalized Ads.txt Specification version 1.0.1. Click the button below to view the spec. Check out our new blog post announcement here.


As part of a broader effort to eliminate the ability to profit from counterfeit inventory in the open digital advertising ecosystem, Ads.txt provides a mechanism to enable content owners to declare who is authorized to sell their inventory.

Previous Version: Ads.txt Spec Version 1.0 | Blogpost

What is the ads.txt project?

The mission of the ads.txt project is simple: Increase transparency in the programmatic advertising ecosystem. Ads.txt stands for Authorized Digital Sellers and is a simple, flexible and secure method that publishers and distributors can use to publicly declare the companies they authorize to sell their digital inventory.

By creating a public record of Authorized Digital Sellers, ads.txt will create greater transparency in the inventory supply chain, and give publishers control over their inventory in the market, making it harder for bad actors to profit from selling counterfeit inventory across the ecosystem. As publishers adopt ads.txt, buyers will be able to more easily identify the Authorized Digital Sellers for a participating publisher, allowing brands to have confidence they are buying authentic publisher inventory.

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The IAB Tech Lab OpenRTB Working Group has developed the ads.txt spec. Questions can be sent to

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