How to check your app-ads.txt.

Five steps

1. Find your developer website. It is the website field on your App Store and Google Play listings. The file has to live at the root of that exact domain, for example https://yourdomain.com/app-ads.txt. A file on another domain, or under a path, is not what crawlers check.
2. Open the file. Load it in a browser and check that you see plain text, not a web page. In a terminal, the first command below should print 200 and a text content type.
3. Check each line. Every record has an ad system domain, your account ID with that seller, DIRECT or RESELLER, and usually a certification authority ID, separated by commas.
4. Compare with each network’s own instructions. For every ad network you use, get your lines from its dashboard or help centre (cards below). Those lines carry your own account IDs, so you cannot copy them from this reference.
5. Re-check after any change. Whenever you add an app, a network or a mediation partner, or move your site. Networks and ad buyers crawl the file on their own schedule.

curl -sSL -o /dev/null -w '%{http_code} %{content_type} %{url_effective}\n' https://yourdomain.com/app-ads.txt

curl -sSL https://yourdomain.com/app-ads.txt | grep -i 'applovin.com'

Common mistakes

• The file is on a different domain from the one in the store listing, or only on a www or subdomain version that is not the listed address.
• The URL returns a 200 status with an HTML page (a custom “not found” page) instead of plain text.
• Placeholder values such as pub-0000000000000000 were left in after copying a template.
• Partners that are no longer used are still listed, or a newly added network’s lines are missing.
• The file sits behind a redirect chain, a login or a bot block. Network documentation (for example InMobi’s) describes how many redirects its crawler follows.
• The record separators or the DIRECT/RESELLER values are mistyped.

The standard is the IAB Tech Lab’s Authorized Sellers for Apps (app-ads.txt) v1.0, an extension of ads.txt. Later ads.txt versions added variables such as OWNERDOMAIN and MANAGERDOMAIN, which some networks ask for.

Network by network

For each network: where to find your lines, the official page to follow, and what the leading publishers’ files show. “Certification ID” is the fourth field most often seen on that network’s lines in the files collected for this reference. Compare it with the network’s own documentation before relying on it.

Reference only, not advice. Network instructions change; follow the linked pages. Back to the reference library and downloads.