The ads.txt file, short for Authorized Digital Sellers, is an initiative by the Interactive Advertising Bureau (IAB) to improve transparency and combat fraud in the digital advertising ecosystem.
It’s a simple text file that publishers place in the root directory of their website. The file lists all the companies that are authorized to sell or resell a publisher's digital ad inventory. This enables advertisers to verify that they are purchasing legitimate ad space from authorized sellers, reducing the risk of fraud, such as domain spoofing or unauthorized reselling of ad placements.
Who uses it?
Some of the key platforms that either require or strongly encourage the use of ads.txt include:
- Google AdSense: While not mandatory, Google highly recommends the use of ads.txt. Publishers without it may experience errors or delays in revenue reporting. It’s especially encouraged to improve transparency and reduce counterfeit ad inventory.
- Google Ad Manager: Google’s ad management platform also strongly encourages the use of ads.txt to ensure legitimate ad selling.
- Amazon Publisher Services: Another major player in digital ads that suggests the use of ads.txt to prevent unauthorized sellers from benefiting from fraudulent ad space sales.
- AppNexus (Xandr): AppNexus requires ads.txt to ensure that advertisers are buying from legitimate sellers.
- PubMatic: This platform also supports ads.txt to protect against ad fraud and ensure transparency.
- OpenX: OpenX is another ad exchange that requires ads.txt to ensure that advertisers are purchasing legitimate inventory.
Other platforms and ad exchanges like Rubicon Project, Sovrn, and Index Exchange also support and encourage the use of ads.txt to protect against unauthorized ad sales and improve the integrity of the ad buying process.
While ads.txt is not mandatory for all platforms, it is widely adopted across the industry, and failure to implement it may limit your ability to fully monetize your ad inventory.
Webflow
Webflow does not directly support ads.txt, but since it is not explicitly a security file, redirects often work.
Webflow has recommended this approach;
https://share.getcloudapp.com/v1um4rqz
- Create your ads.txt file, with the content you want
- Upload it to your site assets
- Get the URL of the uploaded asset
- Create a redirect from
/ads.txtto your URL - Publish your site
Some platforms like Google Adsense do not seem to support the redirect, in which case you can use a reverse proxy solution like Sygnal's Hyperflow to deliver your ads.txt file reliably.
