What is Ads.txt? ads.txt stands for Authorized Digital Sellers. It’s a simple text file placed on a website’s root domain that tells advertisers which companies are allowed to sell that site’s advertising inventory. How ads.txt works? A website owner uploads a file called ads.txt to the root of their domain. Example: https://example.com/ads.txt The file lists authorized ad networks or exchanges allowed to sell the site's ads. Advertisers and DSPs check this file