sellers.json Inspector
Enter an exchange or SSP domain to fetch its sellers.json through the FizzKit relay (with automatic www. fallback and content-type checks), or paste a document. The tool validates the top-level schema and every seller — duplicate seller_id, missing name/domain on non-confidential entries, confidential entries that disclose data, passthrough rules, duplicate publisher domains — in a searchable, sortable table with CSV export and a cleaned copy. The Cross-check tab takes a publisher's ads.txt (pasted or fetched by domain), fetches every exchange's sellers.json it references, and verifies that each account ID exists with a compatible seller_type. The Supply chain tab resolves an OpenRTB schain hop by hop.
Related tools
ads.txt / app-ads.txt Validator
Fetch any domain's ads.txt or app-ads.txt, validate it against the IAB 1.1 spec, follow SUBDOMAIN pointers, and cross-check every line against exchange sellers.json files.
OpenRTB Inspector
Validate & annotate OpenRTB 2.6 BidRequest and BidResponse JSON.
OpenRTB Request Builder
Build OpenRTB 2.6 bid requests with a form or JSON, then send them to any bidder and inspect the response.
RTB Bidder Sandbox
A live OpenRTB bidder endpoint that captures every bid request and answers with bids, no-bids, custom templates or timeouts.
How to use sellers.json Inspector
- 1Type an exchange domain (e.g. pubmatic.com) and press Fetch — the tool loads https://domain/sellers.json via the relay, falling back to www. (known off-domain files like Google's are mapped automatically).
- 2Review the validation summary and the seller table; search, filter by seller_type and click a column header to sort.
- 3Open Cross-check ads.txt, paste or fetch a publisher's ads.txt, and run it to verify every line against each exchange's sellers.json.
- 4Open Supply chain, paste an OpenRTB schain (JSON, serialized, or asi/sid lines) and press Resolve to check each hop.
- 5Export CSV or copy the cleaned sellers.json.
About sellers.json Inspector
Enter an exchange or SSP domain to fetch its sellers.json through the FizzKit relay (with automatic www. fallback and content-type checks), or paste a document. The tool validates the top-level schema and every seller — duplicate seller_id, missing name/domain on non-confidential entries, confidential entries that disclose data, passthrough rules, duplicate publisher domains — in a searchable, sortable table with CSV export and a cleaned copy. The Cross-check tab takes a publisher's ads.txt (pasted or fetched by domain), fetches every exchange's sellers.json it references, and verifies that each account ID exists with a compatible seller_type. The Supply chain tab resolves an OpenRTB schain hop by hop.
sellers.json Inspector is part of FizzKit — a collection of focused developer and ad-tech tools. This tool uses the FizzKit relay to fetch public URLs on your behalf (so browser CORS rules do not get in the way); fetched content is returned to your browser and not stored.