Declare authorized sellers

ads.txt/app-ads.txt FAQs

Expand all  Collapse all

What information should be in an ads.txt/app-ads.txt file?

The text file includes separate lines for each exchange or SSP that is authorized to sell your inventory. Each of these lines should contain three pieces of data (plus a fourth optional field), in the format:

<Field #1>, <Field #2>, <Field #3>, <Field #4>

  • <Field #1>: The canonical domain name of the system where bidders connect. This may be the operational domain of the system, if it’s different than the parent corporate domain, to facilitate WHOIS and reverse IP lookups to establish clear ownership. The SSP or exchange may publish the domain name to use.

    For Google seller accounts, the domain name is always

  • <Field #2>: The publisher identifier associated with the seller or reseller account for the system in field #1. This must contain the same value as that specified in an SSP or exchange transaction (such as OpenRTB bid requests). Typically, in OpenRTB, this is the field. For OpenDirect, it is typically the publisher’s organization ID. 

    For Google seller accounts, use the publisher ID displayed in each account (for example, pub-0000000000000000). To find this ID:

    Only include the pub- prefix and the 16-digit numeric code in your declaration. Delete the product-specific prefix (for example, ca- or ca-video-). If you monetize through multiple Ad Manager and/or AdSense accounts, you must include a separate row for each account, with its corresponding pub- code.

    Domains/apps hosting an ads.txt/app-ads.txt file where the seller’s publisher ID isn’t listed are no longer monetized through Ad Manager, and Google no longer buys ads on such sites/apps.

    Updating your ads.txt/app-ads.txt files to include publisher IDs for each site you want to monetize is recommended. Learn how to update ads.txt/app-ads.txt in Ad Manager.

  • <Field #3>: The type of account or relationship. This field should be treated as case-insensitive when interpreting the data.
    • A value of 'DIRECT' indicates that the publisher (content owner) directly controls the account indicated in field #2 and has a direct business contract between the publisher and the advertising system.

      Google publishers who directly control the account indicated in field #2 should specify 'DIRECT'.

    • A value of 'RESELLER' indicates that the publisher has authorized another entity to control the account indicated in field #2 and resell their ad space via the system in field #1.

      Google publishers who don't directly control the account indicated in field #2 should specify 'RESELLER'. For example, an Ad Manager account using Scaled Partner Management should specify 'RESELLER' for inventory the account doesn't directly manage.

  • <Field #4>: (Optional): A unique identifier for the advertising system within a certification authority, which maps to the entity listed in field #1. One certification authority is the Trustworthy Accountability Group (TAG), and the TAG ID would be included here.

    For Google seller accounts, the TAG ID is f08c47fec0942fa0.

Where should my ads.txt/app-ads.txt file be?

ads.txt/app-ads.txt files should be hosted in the root domain.

How does Google enforce ads.txt/app-ads.txt files?

Google uses the content of any ads.txt/app-ads.txt files hosted on a root domain/app to determine which seller accounts are allowed to serve ads on that domain/app.

Google runs an auction and returns a winning ad for requests on sites where an ads.txt/app-ads.txt file exists with a correctly listed publisher identifier. If the identifier in the file is incorrect, an auction is not run for that request.

New and updated ads.txt/app-ads.txt files are detected automatically, but changes may take up to 48 hours.

What if the ads.txt/app-ads.txt file is hosted on a subdomain?

Google crawls and enforces ads.txt and app-ads.txt files placed on subdomains, where one exists, and is referenced from the ads.txt file on the root domain.

In Ad Manager, the ads.txt management tool does not yet show a list of crawled subdomains.

How often is ads.txt/app-ads.txt crawled and distributed?

Every domain that Ad Manager receives ad requests from is crawled at least once a day. A snapshot of all crawled data is compiled at least once a day, and that snapshot is subsequently distributed to all ad servers.

Ad Manager displays the last fetched ads.txt/app-ads.txt version. Note that it might take additional time until the displayed ads.txt/app-ads.txt crawl result is distributed to the ad servers.

Does Google support redirects?

Google supports a single HTTP redirect to a destination outside the original root domain (for example, re-directs to See the IAB update.

Multiple redirects are also supported, as long as each redirect location remains within the original root domain. For example:

  • redirecting to
  • redirecting to
  • redirecting to
My CMS doesn't let me place a file on my root domain. What should I do?

Contact your CMS provider who should provide you with the facility to host an ads.txt/app-ads.txt file on your behalf.

What if Ad Manager does not detect the ads.txt/app-ads.txt file posted on my domain?

A domain may have an ads.txt/app-ads.txt file posted but may still show in the Ad Manager ads.txt/app-ads.txt management tool with a status of "no ads.txt found". This may happen due to an incorrect ads.txt/app-ads.txt implementation or other crawl-related reasons. Learn more about how to ensure your ads.txt/app-ads.txt files can be crawled.

What if buyers see blank or empty URLs in bid requests?

Here are some reasons why the URL in a bid request may be blank or empty:

  • One of your root domains may be missing an ads.txt/app-ads.txt file. Google uses the ads.txt/app-ads.txt file on a domain to verify that a publisher is authorized to monetize the domains sent to buyers in a bid request. If the ads.txt/app-ads.txt file for a domain is missing, bid requests may include a blank or empty URL. 

    You should upload an ads.txt/app-ads.txt file to each domain individually. Review Admin and then Ads.txt management to confirm that an ads.txt/app-ads.txt file has been uploaded to each of your domains.
  • There could be an implementation error if an ads.txt/app-ads.txt file has been posted on a domain but it isn’t detected in Ad Manager. Learn more about ads.txt/app-ads.txt management in Ad Manager and ensuring your ads.txt/app-ads.txt files can be crawled
  • There may be a problem with the way the ‘page_url’ override attribute of the Google Publisher Tag or passbacks are implemented. This may result in an invalid overridden URL value being passed in ad requests to DFP and a blank or empty URL in bid requests received by buyers.
What if I see a domain that I don't recognize?

Here are some reasons why the "Ads.txt" page might list a domain name that you don't recognize:

  • Your ad code is nested within multiple iframes or you're using an ad server, yield manager, or other Supply-Side Platform (SSP) that embeds your ad code in iframes. If your ad code is nested within an iframe, we are not able to determine the correct site information for an ad request. This can happen when your page includes an iframe that points at another URL on your site containing the tag to be shown.
  • Sites that serve the contents of your site from their own domain. For example, Google cached search results, Google Accelerated Mobile Pages (AMP) Cache, and Google Translate may retrieve your content, then serve it from a Google domain, without iframes.

  • Web pages forwarded in email clients.

  • Duplication (in other words, copy and pasting) of content from one publisher to another.

Suggested actions for unrecognized domains:

  • If your ad code is nested within multiple iframes, you may need to pass the URL of the page that users are browsing.
  • If you're using an ad server, yield manager, or other Supply-Side Platform (SSP) and you see unrecognized domains, contact the SSP's account management team and ask them the best way to ensure that the correct site information is passed in your ad requests.
How do I set up an ads.txt/app-ads.txt file for WordPress?

Consider using a plugin to create your ads.txt/app-ads.txt file in WordPress. If you already use a plugin to place ads, it might include a feature to create your ads.txt file. This search can help you get started.

How do I set up an ads.txt/app-ads.txt file for Blogger?

See the Blogger Help Center for instructions.

Why is my domain not listed in the table?

Domains (subdomains or root domains) are only shown in the table if they have more than 100 queries in the last 7 days.

Was this helpful?

How can we improve it?
Clear search
Close search
Google apps
Main menu
Search Help Center