What is ads.txt?

What is ads.txt


With the rise of programmatic ad buying, brand safety has become the talk of the town, making the IAB Tech Lab Ads.txt initiative appearing in the very nick of time. Being both easy to adopt and secure, Ads.txt is one of the major brand safety tools for declaring who is authorized to sell traffic from website.

Ads.txt resembles a public record of Authorized Digital Sellers, as in the Business Insider sample, aimed at preventing proliferation of counterfeit and unauthorized ad impressions transacted via domain spoofing across the digital advertising market.

Based on the Ads.txt Specification version 1.0.1 released by the IAB Tech Lab in September, 2017 all data in an ‘/ads.txt’ file should be ‘text/plain’, residing at a domain root folder and comprising the following information:

  • Domain name of the advertising system (Required)
  • Publisher’s Account ID (Required)
  • Type of Account/ Relationship (Required)
  • TAG Certification Authority ID (Optional)
  • Comments (Optional)

An ‘/ads.txt’ file can also contain several variable fields, such as:

  • Contact information (Optional)
  • Subdomain (Optional)

The information required for an ‘/ads.txt’ file is available in the OpenRTB protocol and OpenDirect API, making it easy to collect and work with.

As publishers sell their inventory through a variety of sales channels, ads.txt supports the following types of supplier relationships:

  • A domain owner that sells ads on exchanges, using own account.
  • A network or sales house that sells programmatic ads on behalf of domain owners.
  • A content syndication partnership in which multiple authorized sellers represent the same inventory.

For more details, please check out our explainer article – Why it is important to implement ads.txt?