Free Supply Chain Compliance Validators

Misconfigured ads.txt or sellers.json files are one of the most common—and entirely preventable—causes of revenue leakage in programmatic advertising. If a demand-side platform (DSP) cannot verify the supply chain, many buyers will refuse to bid. Bidkernel provides free, built-in validation tools to monitor your compliance proactively and prevent costly mistakes.

Why Validation Matters Link to section

The programmatic ecosystem runs on trust. Buyers need to know they are purchasing authentic inventory from authorized sellers. This is managed through two primary specifications established by the IAB Tech Lab:

  • Ads.txt (Authorized Digital Sellers): A file hosted on your domain that explicitly lists which exchanges and seller IDs are authorized to sell your inventory.
  • Sellers.json: A file hosted by the exchange (or intermediary) that lists all of their authorized publishers, completing the two-way verification loop.

Even a single typo, a misplaced comma, or an unmapped relationship can cause a DSP to drop a bid. Worse, as you scale and add more demand partners, managing these files manually becomes highly error-prone.

Bidkernel's Free Tools Link to section

We believe compliance shouldn't be hidden behind a paywall. Accessible from the Tools section in your dashboard, our validators check your live files exactly as a crawler would.

Ads.txt Validator Link to section

The Ads.txt Validator allows you to enter any domain to fetch, parse, and validate its ads.txt file in real-time. It performs the following checks:

  • Syntax Errors: Identifies malformed lines and missing fields.
  • Field Validation: Checks domain format, non-empty account IDs, valid relationships (DIRECT or RESELLER), and TAG-ID certification format.
  • Duplicate Detection: Flags repeated domain/account/relationship entries.
  • Declaration Checks: Recognizes contact, ownerdomain, managerdomain, and subdomain declarations, and warns when recommended ones are missing.

Sellers.json Validator Link to section

The Sellers.json Validator lets you enter a domain — the tool fetches sellers.json from that domain's root — or paste file contents directly to parse and validate them.

  • Spec Compliance: Checks required and recommended fields from the IAB Tech Lab sellers.json spec, including valid seller_type values (PUBLISHER, INTERMEDIARY, or BOTH).
  • Duplicate Detection: Flags repeated seller_id entries.
  • Confidential Sellers: Handles confidential sellers per the IAB spec (seller_id may be listed without name and domain).
  • Manual Cross-Checks: You can fetch any partner's sellers.json to confirm your listing manually.

Use Them Anywhere Link to section

Even if you aren't using Bidkernel's Edge infrastructure to natively host and auto-generate these files, you can (and should) use these validators. They are completely free. Run your existing hosting through our tools to ensure your setup is fully compliant before you launch new demand partners or push updates to production.

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