Validate your ads.txt, line by line.
Paste your Authorized Digital Sellers file and check it against the IAB Tech Lab spec. Every error, warning and notice, with the exact line and how to fix it. Nothing leaves your browser.
Parsed entirely in your browser — your file is never uploaded.
Your results will appear here
Paste a file or load an example, then run the validator. It checks every line locally — no upload, no network.
A public list of who's allowed to sell your inventory.
Authorized Digital Sellers — ads.txt — is an IAB Tech Lab standard. You publish a plain-text file at yourdomain.com/ads.txt naming every advertising system authorized to sell your inventory and the account IDs they use.
Buyers crawl that file to confirm a bid request is legitimate, which shuts the door on domain spoofing and unauthorized reselling. If a seller isn't in your ads.txt, careful buyers simply won't trust the impression — so an accurate file is the difference between a bid and a skip.
Every data record has the same four fields.
A record is one line of comma-separated values. The first three fields are required; the fourth is optional. Blank lines and anything after a # are ignored as comments.
- 1 Required
google.comAdvertising system domain
The canonical domain of the SSP or exchange — a bare host like google.com, with no https:// or path.
- 2 Required
pub-0000000000000000Publisher account ID
Your seller or account ID within that advertising system, exactly as they issued it.
- 3 Required
DIRECTRelationship
DIRECT if you contract with the system directly, RESELLER if they're authorized to sell on your behalf.
- 4 Optional
f08c47fec0942fa0Certification authority ID
The system's TAG-ID — usually 16 hexadecimal characters. Optional, but it strengthens the authorization chain.
Beyond records: the declarations buyers also read.
Variables are KEY=value lines that describe the file itself rather than a single seller. The validator recognizes all five from the spec — the two original v1.0 variables and the three added in v1.1 for ownership and management transparency.
CONTACT v1.0 A contact for questions about the file — an email address or URL. Optional but good practice.
SUBDOMAIN v1.0 Points to a subdomain that maintains its own ads.txt, so buyers know to crawl it too.
OWNERDOMAIN v1.1 The root domain of the inventory's owner. One per file — buyers use it to confirm who profits.
MANAGERDOMAIN v1.1 The domain of the exclusive monetization partner, optionally scoped to a country code.
INVENTORYPARTNERDOMAIN v1.1 Names a partner whose sellers.json should also be consulted for indirect inventory.
The errors we see most — and how to fix them.
Every data record needs a relationship as its third field. Add DIRECT or RESELLER after the account ID.
Field one is a bare host. Write google.com, not https://google.com/ads or www.google.com.
Consumers read it case-insensitively, but the spec's canonical form is upper-case. Write DIRECT and RESELLER.
The same domain, account ID and relationship listed twice adds noise and can hide a copy-paste mistake. Remove the extra line.
Only CONTACT, SUBDOMAIN, OWNERDOMAIN, MANAGERDOMAIN and INVENTORYPARTNERDOMAIN are recognized, and each needs a value after the =.
Not an error, but add the TAG-ID wherever the advertising system publishes one — it makes the authorization harder to forge.
We keep your authorization chain clean, so every impression can be bought.
RevIQ manages your ads.txt and sellers.json entries as part of onboarding, verifies the seller relationships behind every dollar, and shows you which demand paths actually pay. Transparent fees, traceable spend, real inventory.
- Managed ads.txt and sellers.json, kept in sync as your partners change
- Verified DIRECT and RESELLER relationships, end to end
- Traceable payouts — see the fee taken on every impression
ads.txt, answered
The questions publishers ask most about Authorized Digital Sellers.
Request accessIs this ads.txt validator free?
Yes. Paste your file and validate as often as you like. It runs entirely in your browser, so your file is never uploaded to a server.
Where should my ads.txt file live?
At the root of your domain — https://yourdomain.com/ads.txt — served as text/plain. Buyers only look there, so it can't sit in a subfolder.
What's the difference between DIRECT and RESELLER?
DIRECT means you have a direct contract with that advertising system for your inventory. RESELLER means you've authorized them to sell it on your behalf through another party.
Does it check both ads.txt v1.0 and v1.1?
Yes. It understands v1.0 records and the CONTACT and SUBDOMAIN variables, plus the v1.1 additions: OWNERDOMAIN, MANAGERDOMAIN and INVENTORYPARTNERDOMAIN.
Can I validate a live domain by URL?
Browsers block cross-origin requests to most ads.txt files, so fetching by URL isn't reliable here. Open yourdomain.com/ads.txt, copy the contents, and paste them above — it's exactly the same check.
