Learn · How to fix
What does it mean when an ad system domain in app-ads.txt doesn't resolve?
Updated Oct 7, 2026 · data from 12 App Store genres · top free + top grossing charts · US · iOS + Android
Short answerThe domain in the first field of the line has no working DNS record: the ad system may have been retired or merged, or the domain is misspelled. The line can't be validated.
434 of 883
ad-monetized top US apps in this index have this finding (49%)
Why it matters
Lines for domains that don't exist add nothing for buyers.
If such a domain is registered again by someone else, its new holder would appear authorized by your file, which is a reason to remove these lines rather than leave them.
How to fix it
- Check the domain for typos (for example, a missing or doubled part).
- If the company merged into another ad system, replace the line with the one the new owner provides.
- Otherwise remove the line.
Before
appnexus.comappnexus.com, 1234, RESELLER
After
appnexus.com, 1234, RESELLER
Apps with this finding
Each report lists the exact lines involved.
- Word Search Explorer® · PlaySimple Games Pte Ltd
- Sled Surfers · CRAZY LABS BY TABTALE , G.P.
- Glow Fashion Idol · CRAZY LABS BY TABTALE , G.P.
- Lamar - Idle Vlogger · CRAZY LABS BY TABTALE , G.P.
- My Sticker Room - Decor Game · SayGames LTD
- Vita Mahjong · VITA STUDIO PTE. LTD.
- Mystery Town: Merge Games · Cedar Co., Limited
- Meowdoku! · OAKEVER GAMES PTE. LTD.
- Amaze GO! · OAKEVER GAMES PTE. LTD.
- Colorever: Gem Art Puzzle · OAKEVER GAMES PTE. LTD.
- Jigsawcard Solitaire Puzzle · OAKEVER GAMES PTE. LTD.
- Block Blast！ · ARETIS LIMITED
Questions
How do you decide a domain doesn't resolve?
Neither the domain nor its www host returns an address in DNS at crawl time.
Related
Based on the IAB Tech Lab ads.txt/app-ads.txt and sellers.json specifications. Numbers are automated observations of public files on the date above.