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Everything Publishers Need to Know About Ads.txt

September 27, 2021

If you’re a publisher, you’ve likely heard of ads.txt before. As ad fraud becomes more prevalent in the advertising industry, authorities, publishers, advertisers, and networks keep working to develop solutions to mitigate its costly effects. Ads.txt is one of the ways the International Advertising Bureau (IAB) uses to fight common forms of ad fraud like domain spoofing and unauthorized inventory sales.

Unfortunately, many publishers don’t quite understand what ads.txt is, how to install it, or the benefits. In this article, we’ll explain:

  • Ads.txt and how it works.
  • How to create and install your file.
  • How you can create an ads.txt file in WordPress.
  • Why the file benefits publishers.
  • The risks involved.

We’ll also cover a few frequently asked questions to help you understand everything you need to know about ads.txt.

What Is the Ads.txt File and How Does It Work?

Simply defined, ads.txt is a text file that allows publishers to restrict their ad inventory to authorized sellers. The IAB Tech Lab developed it as part of its transparency program to fight ad fraud in general and prevent domain spoofing in particular. 

Publishers can use the file to restrict ad inventory, filtering out unauthorized inventory sales and resales. Doing so ensures that advertisers spend their money on valuable ad space while protecting a publisher’s revenue.

The process matches the publisher’s account ID with the one listed in the ads.txt file. If it’s a match, the advertiser’s ads will be delivered and displayed. If it’s not a match, the ads won’t appear.

How to Create and Install Ads.txt

Creating an ads.txt file is relatively easy. You can use any text editor, including Notepad or Microsoft Word, to create the file. However, filling it out can seem a little tricky since you must use a very specific syntax as defined by IAB.

Each line must contain the following:

  • The domain of the network supplying the ads. If there’s more than one domain, only use the canonical domain.
  • Your account ID. Networks, exchanges, and monetization platforms will provide you with a unique publisher ID.
  • Whether they’re a direct partner or reseller. If you’ve signed a contract directly with a network, they’ll be a DIRECT partner. However, if you’ve authorized them to sell inventory on your behalf to other partners, they’ll be listed as a RESELLER.

You can also include an optional fourth field, which is the ID of the advertising platform. Remember to list only one supplier per line and to separate each field with a comma. For example, if you include your AdSense account, the line will look like this:, pub-0000000000000000, DIRECT, f08c47fec0942fa0

Since it’s a public file, you can look at examples from any other big publisher to understand how it works. Here’s an example of our ads.txt file at Softonic:

How to Upload Ads.txt To Your Domain Root

To work correctly, the ads.txt file needs to be uploaded to the root folder of your domain. You can do this via FTP or through the File Manager if you have a control panel. Regardless of which method you use, you’ll need to access the file system, which will look something like this:

Select the public­_html folder to open it. This is where your ads.txt file needs to be. If you’re using a file manager, you should have the option to upload a new file. Select the button, and then navigate to where you’ve saved the file. Choose to upload the file, and that’s it!

If you’re using an FTP client, you’ll need your host domain, port, control panel username, and password to create a connection. Once connected, again navigate to the public_html folder and upload your file as usual.

Installing Ads.txt in WordPress

You can still use the process outlined above, even if you’re using WordPress. However, there’s an alternative way to add an ads.txt file in WordPress using a plugin.

First, start by installing and activating the plugin: Ads.txt Manager. Once activated, select the “Settings” option in the menu panel on the left. From there, click on the “Ads.txt page” option to start configuring your file.

Now you just need to add in the lines as before, select “Save Changes,” and you’re done! If you need to update the file in the future, you can simply navigate back to the plugin and make the necessary changes.

Why Having an Ads.txt File Benefits Publishers

In 2020, advertisers lost $35 billion to ad fraud. However, publishers are victims of ad fraud as much as consumers and advertisers. Not only do they lose revenue to these fraudulent advertisements, but they also lose the trust of advertisers, monetization partners, and networks.

By setting up an ads.txt file, publishers can prevent illegitimate and unauthorized sellers from using their ad inventory. That helps to prevent ad fraud, protecting the publisher’s revenue and reputation.

Are There Risks to Using Ads.txt?

An ads.txt file needs to be 100% accurate and must be kept up to date. If you don’t list all your monetization partners within the file, they won’t be able to bid on your inventory. That can cause a significant loss in revenue since these “unauthorized sellers” won’t be able to display ads on your website. If you decide to use ads.txt, ensure that you regularly update it to prevent any errors.

Frequently Asked Questions

We understand that you may still have a few questions about ads.txt. Below we’ve answered a few of the most common ones we’ve encountered.

Is the Ads.txt File Mandatory?

No, it’s not. However, it’s an excellent way to safeguard your ad inventory and protect your income from being stolen by fraudsters. We advise all publishers to have a properly configured and regularly updated ads.txt file.

How Often Does Google Crawl for The Ads.txt File?

Once the file is set up on the domain, Google will crawl it every 24 hours. If you use caching to speed up your website, it may take that long to remove old ads or for newly approved sellers’ ads to start appearing.

How Do You Set Up App-Ads.Txt?

App-ads.txt is very similar to ads.txt since it also needs to be uploaded to a website. However, you need to follow a few additional steps to ensure that it’s correctly detected and verified by AdMob. Luckily, Google clearly explains the process.

How To Find or Update Your Ads.Txt File in WordPress

If you use the plugin we mentioned earlier, you can make the updates and changes within it. However, you can also navigate to the file within the root folder in File Manager.


Fraud is a growing concern in the ad industry, and advertisers and publishers alike are fighting this digital epidemic. Ads.txt allows publishers to lower the risk and even prevent domain spoofing and the sale of counterfeit ad inventory. While it’s neither mandatory nor foolproof, it’s an excellent place to start if you want to fight ad fraud and protect your revenue.

is the Adtech Product Lead at Softonic. As Adtech Product Lead, Richard is responsible for improving overall revenue and ad performance for all our properties, including Rev·Amp, Softonic’s new publisher monetization platform. Within Rev·Amp Richard oversees development for the Rev·Amp monetization stack, both innovations and the improvement of existing technologies.
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