app-ads.txt checker

What is app-ads.txt?

app-ads.txt (Authorized Sellers for Apps) is an IAB Tech Lab standard that lets app developers declare which companies may sell their ad inventory. Ad networks such as AdMob, AppLovin, Unity and Meta Audience Network read it to make sure an ad request really comes from your app. If it's missing or wrong, advertisers can skip your inventory and your ad revenue drops.

Where does the file go?

Ad networks take the developer website from your Google Play or App Store listing and request /app-ads.txt at the root of its domain. For a website of https://www.example.com/apps, put the file at https://example.com/app-ads.txt (and make www.example.com/app-ads.txt serve it too), as text/plain. This checker looks at your website's own host first, then at its root domain.

File format

One record per line: ad system domain, your account ID with that system, the relationship (DIRECT for your own account, RESELLER for partners that resell it) and an optional certification authority ID. Lines starting with # are comments.

# AdMob
google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0
# A mediation partner
applovin.com, 0123456789abcdef, DIRECT

Common problems

• No developer website in the store listing, or a different domain than the one hosting the file.
• The file is on a different domain than the website in the store listing, or redirects to another domain.
• The site returns an HTML page (often a site builder's 404 page) instead of plain text.
• The AdMob ID is written as ca-app-pub-… or includes the ~app id part. Use pub- and the 16 digits only.
• AdMob hasn't re-crawled yet. After fixing, it can take up to 24 hours to update.