How this audit works

This tool fetches a publisher's ads.txt and app-ads.txt files directly, parses every declared authorized-seller record, and cross-references each one against the live sellers.json file published by the corresponding ad system — following the IAB Tech Lab's ads.txt and sellers.json specifications.

Verification statuses

• Verified The account ID exists in the ad system's sellers.json, is not confidential, and its declared domain/seller_type is consistent with the ads.txt relationship type.
• Domain mismatch A DIRECT relationship where the sellers.json domain field doesn't match the publisher's own domain — often a resold or Open-Bidding-style path mislabeled as direct.
• Type mismatch The seller_type in sellers.json (PUBLISHER vs INTERMEDIARY) is inconsistent with the declared DIRECT/RESELLER relationship.
• Not found The account ID isn't listed in that ad system's sellers.json at all — unverifiable.
• No sellers.json The ad system domain doesn't serve a sellers.json file, or it couldn't be fetched.
• Confidential The seller record exists but is marked confidential — name and domain are intentionally withheld.

ads.txt vs. app-ads.txt inconsistencies

When the same (ad system, account ID) pair appears in both files but is declared DIRECT in one and RESELLER in the other, that's flagged as a real inconsistency. Being present in only one of the two files is normal (many ad systems are web-only or app-only) and is not flagged.

Limitations

Analysis reflects a live, point-in-time fetch of each file — ads.txt and sellers.json both change frequently. Some large ad systems host sellers.json on a different subdomain than their ads.txt-declared domain, which will show as "no sellers.json" here even though a valid file exists elsewhere. Batch audits are capped at 25 domains per run to keep turnaround reasonable. The rate limiter and usage counters below are best-effort and scoped to a single warm serverless instance — see note.

Live session stats

Counts reflect only this warm serverless instance and reset whenever a new one spins up — an operational signal, not a durable analytics total.

Privacy

This tool does not collect, store, or sell any personal data. There are no cookies, no analytics trackers, no accounts, and no logins.

When you enter a domain, the only action taken is a server-side fetch of that domain's publicly published ads.txt / app-ads.txt file and the sellers.json files hosted by the ad systems it references. These are already public files by design — the ads.txt and sellers.json specifications exist specifically so anyone can read them.

Domains you enter and the results returned are not written to a database, not logged with any personal identifier, and not shared with or sold to any third party. The lightweight, in-memory usage counters shown under Live session stats (Methodology tab) exist only to monitor operational health — they store counts, not domain names, and reset whenever the server instance restarts.

Data sources

Every result comes directly from the publisher's own ads.txt/app-ads.txt file and the sellers.json files published by the ad systems referenced within it, fetched live at request time. This tool does not maintain its own database of sellers, publishers, or historical records.

No affiliation

This is an independent, unofficial tool. It is not affiliated with, endorsed by, or officially connected to the IAB Tech Lab or any advertising company that may appear in its output.

Disclaimer

Results reflect a live, best-effort, point-in-time read of third-party files that are outside this tool's control and can change or become temporarily unavailable at any time. Nothing shown here is a compliance certification, legal advice, or a guarantee of accuracy. Use at your own discretion.