Ads.txt Generator & Validator
Generate and validate IAB Tech Lab compliant Authorized Digital Sellers (ads.txt) files — entirely on this device.
# ads.txt - Authorized Digital Sellers (IAB Tech Lab) CONTACT=adops@example.com google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0 # AdSense / Google Ad Manager appnexus.com, 1234, RESELLER, f08c47fec0942fa0
Do it offline:$
How to use it
- Add advertising exchange records including exchange domain (google.com), publisher ID, relationship (DIRECT or RESELLER), and optional TAG certification ID.
- Optionally declare a CONTACT email directive or SUBDOMAIN delegated pointers.
- Review the syntax diagnostics identifying missing commas or incorrect relationship strings.
- Switch to Validator Mode to paste and verify existing production ads.txt files.
- Download or copy the generated ads.txt and host it at your domain root (https://example.com/ads.txt).
Generate and validate ads.txt records according to IAB Tech Lab specifications to protect web publisher programmatic ad revenue from domain spoofing and inventory fraud.
How it works
Ads.txt (Authorized Digital Sellers) is an IAB Tech Lab standard allowing publishers to publicly declare who is authorized to sell their digital ad inventory.
Field 1 is the canonical domain name of the advertising system (e.g. google.com, openx.com).
Field 2 is the publisher's identifier within that advertising system.
Field 3 specifies the relationship: DIRECT indicates the publisher controls the account; RESELLER indicates an authorized third-party manages the inventory.
Field 4 is an optional Trustworthy Accountability Group (TAG) certification authority ID.
Examples
Every example on this page is executed against the same engine that powers the tool, on every build.
Gotchas worth knowing
Common errors
FAQ
Where should the ads.txt file be hosted?
The ads.txt file must be accessible via HTTP/HTTPS at the root level of your website (e.g. https://yourdomain.com/ads.txt) with a text/plain MIME type and HTTP 200 OK status.
What is the difference between DIRECT and RESELLER?
DIRECT means you (the domain owner) directly operate and control the account tied to the publisher ID. RESELLER means an ad network, monetization partner, or agency manages and sells your inventory on your behalf.
Will having errors in ads.txt hurt my ad revenue?
Yes! Major demand-side platforms (DSPs) such as Google Display & Video 360 automatically crawl ads.txt files and refuse to bid on inventory that is not properly authorized in your ads.txt, causing steep revenue drops.