Free tool
Ads.txt Validator
Paste your ads.txt and get every syntax error, malformed record and duplicate,
with the line number. Runs entirely in your browser — nothing is uploaded.
Questions
- What does an ads.txt validator check?
- It checks each line against the IAB Tech Lab ads.txt spec: every record must have three or four comma-separated fields (exchange domain, publisher ID, DIRECT or RESELLER, and an optional certification authority ID). It also flags malformed domains, lowercase relationship values, duplicate records, unknown variable declarations, and missing CONTACT or OWNERDOMAIN lines.
- Does a valid ads.txt guarantee my inventory is authorised?
- No. Ads.txt only declares who you say may sell your inventory. Buyers also check the exchange’s sellers.json to confirm the exchange agrees. A file can be perfectly valid and still contain seller IDs that no exchange recognises, which is why the sellers.json checker exists.
- Where does ads.txt need to live?
- At the root of your domain, served over HTTPS as plain text — for example https://example.com/ads.txt. Crawlers do not follow it from a subdirectory. Subdomains need their own file, or a SUBDOMAIN declaration pointing at one.
- Is my file uploaded anywhere?
- No. This validator runs entirely in your browser. The text you paste is never sent to AdGhost or to any third party.
Want the revenue too?
A clean ads.txt is the floor, not the ceiling. We run the whole stack behind it.