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ads.txt aggregated files – the easy way to fight ad fraud

By Jennifer Derke

Buyers and buy-side ad tech partners must develop a strategy of buying publisher inventory that is sold only by authorized digital sellers, as declared in publisher ads.txt files. IAB Tech Lab’s ads.txt aggregator is a simple, easy-to-use tool that helps by providing efficient delivery of aggregated ads.txt structured data from across a large subset of domains on the web.


For buyers to take advantage of ads.txt, a common approach is to develop a tiered strategy for media buying, depending on campaign reach goals:

  1. if there is an ads.txt file present for a publisher, then only buy that publisher’s inventory from the authorized sellers listed in the file
  2. if there is no ads.txt file present for a publisher, then be cautious about buying this publisher’s inventory


At this phase of adoption, ad tech partners are helping buyers purchase inventory from authorized sellers and also helping sellers understand how they are cutting out fraud by using ads.txt files. Publisher’s ads.txt files should only be cached for seven days—ad tech partners should have frequently updated ads.txt file data, which can be delivered by regularly crawling the web for publisher’s ads.txt files. To deliver services that take advantage of ads.txt, ad tech partners are using the IAB Tech Lab’s ads.txt aggregator to access a large quantity of structured ads.txt files.


If you are interested in using aggregated ads.txt files, you can access the IAB Tech Lab tool via API or portal login. Over 2 million domains with ads.txt files are aggregated and made available in structured, gzipped, .csv files. Subscribers can use ads.txt aggregate files to deliver enhanced reporting to clients to reduce media spend on fraudulent inventory.


Learn more and access the IAB Tech Lab Ads.txt Aggregator tool here:


IAB Tech Lab








Jennifer Derke, Director, Product Management, IAB Tech Lab