Category: Developer tools
ads.txt Generator
Build and validate ads.txt authorized-seller lines
Paste or type ads.txt lines — advertising system domain, publisher account ID, DIRECT or RESELLER, and an optional certification authority ID — and get each line validated against the IAB format, plus a cleaned, normalized ads.txt ready to publish.
| Line | Status | Detail |
|---|---|---|
| 1 | Valid | greenadexchange.com, 12345, DIRECT, d75815a79 |
| 2 | Valid | blueadexchange.com, 4536, RESELLER |
greenadexchange.com, 12345, DIRECT, d75815a79 blueadexchange.com, 4536, RESELLER
Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
ads.txt (Authorized Digital Sellers) lets a publisher declare which ad systems are authorized to sell its inventory, so buyers can filter out spoofed or unauthorized inventory claiming to be yours. Each line needs an ad system's domain, your account ID with that system, and a DIRECT or RESELLER relationship — a typo in the relationship value or a missing field silently breaks that line's validation for buyers. This tool checks each line and flags the ones that won't parse correctly.
How to use it
- Enter one line per advertising system: domain, publisher account ID, relationship, and an optional certification ID.
- Review the validation table — invalid lines are flagged with the reason.
- Copy the cleaned output and publish it at /ads.txt on your domain's root.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- DIRECT or RESELLER — what's the difference?
- DIRECT means you have a direct business relationship with that ad system; RESELLER means the ad system is authorized to sell your inventory through an intermediary rather than directly.
- Where does ads.txt need to be published?
- At the root of your domain, e.g. https://example.com/ads.txt — not in a subdirectory, and not only under www if buyers might crawl the non-www host.
- What's the certification authority ID for?
- An optional TAG-ID or similar identifier for the ad system, used by some verification programs; leave it off if the ad system you're listing doesn't provide one.