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Ads.txt Insights

An ads.txt checker that shows you what to fix

Ads.txt (Authorised Digital Sellers) is the IAB text file at the root of your domain that lists every company allowed to sell your ad inventory. Leave a required line out and buyers can't verify the seller, so they bid less or not at all; leave an old partner in and they can still resell you. Ads.txt Insights in Fusion crawls your file every 5 hours and shows what's missing, duplicated, invalid or untracked, with the exact lines to fix it.

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What we check

Every way an ads.txt file costs you bids

Each crawl validates every line, matches it against what your partners need and checks the file can be found.

Ads.txt problems Fusion checks for, what each means and how to fix it
CheckWhat it meansWhat to do
Missing linesA line one of your demand partners needs isn't in the file. Buyers can't verify that seller, so they bid less or not at all.Copy the missing lines from "Let's fix it" and add them.
Untracked linesA line nothing in your ad stack or third-party list needs. It may be dormant, letting a former partner resell your inventory.Add active partners as third-party requirements, then remove the rest.
Duplicate linesThe same exchange or variable line appears more than once, often from copy-paste or unmanaged reselling.Delete the repeat. Fusion shows which line it copies.
Invalid relationshipThe relationship is something other than DIRECT or RESELLER.Correct the value.
Missing fields or bad IDsA line without an exchange domain, account ID and relationship, or with a badly formatted ID.Rewrite it in the IAB Ads.txt 1.1 format.
File not foundThe file isn't at the root of your domain, sits in a sub-folder, or isn't served over HTTPS.Serve it at https://yourdomain.com/ads.txt.
Wrong content typeThe file is served as HTML, often a 404 page or a rewrite rule, instead of text/plain.Save it as .txt and serve it as text/plain.
Old version cachedYour server or CDN keeps serving the file from before your last change.Clear the cache after every update.
How it works

From crawl to a clean file

  1. 01
    Crawl
    Fusion fetches your ads.txt from the root domain every 5 hours and checks it is served over HTTPS as text/plain.
  2. 02
    Match
    Each line is validated and matched against the lines your demand partners and third-party partners need: required, missing, duplicate or untracked.
  3. 03
    Fix
    "Let's fix it" gives you the missing lines to copy in one go, or "Start from scratch" gives you only the lines you need. Fusion emails you when the file is up to date.
Direct vs reseller

Fewer, more direct paths to your inventory

DIRECT means you hold the account with the exchange; RESELLER means another company sells your inventory through its account. You'll need both, but Exchange Insights shows where the same exchange appears many times, so you can cut paths you don't need.

More unique exchanges

  • Less dependence on any one source of demand
  • More bidders competing, which can push CPMs up
  • Access to specialist and niche buyers

Too many or duplicated exchanges

  • Several paths to the same inventory, so buyers can bid against themselves
  • The same exchange as both DIRECT and RESELLER, which can lead to bidflation
  • Slower verification and a longer, more wasteful supply chain
  • More lines to manage, and more room for old or wrong ones
In Fusion

Keep your ads.txt right without the busywork

Fix it in one go, or let us host it. Either way you hear about changes before they cost you.

Managed Ads.txt

We host an ads.txt file for you and keep it up to date as partners change. Point your domain's ads.txt to it and there's nothing to maintain.

Let's fix it and Start from scratch

Copy every missing line in one go, or replace the file with only the lines you need.

Third-party requirements

Enter the lines your other active partners need in publisher settings. They're tracked from then on, so anything still untracked is safe to flag for removal.

Exchange Insights

Every exchange in your file, with its direct and reseller lines, multiple paths to the same inventory and untracked lines. Export to CSV or Excel.

Ads.txt update alerts

An email when new partners need lines added, and again when your file is back up to date.

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Benchmarking

Compare your share of DIRECT lines and number of unique exchanges with similar publishers and the whole network.

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Ads.txt is part of the free HealthcheckRead the ads.txt guide
Results

Where publishers got to on Fusion

Results are for each publisher's whole Fusion set-up, of which a clean ads.txt is one part.

+1,710%net revenueTimes Higher Education — header bidding, dynamic floors and refresh on a managed stackRead the case study +121%user RPMLondon South East — with +62% net revenueRead the case study +369%average user RPMKelsey Media — on amateurphotographer.com, versus the previous partnerRead the case study
FAQ

Ads.txt questions, answered

What is ads.txt?
Ads.txt (Authorised Digital Sellers) is a plain text file, defined by the IAB Tech Lab's Ads.txt 1.1 specification, that a publisher hosts at the root of its domain to list every company allowed to sell its ad inventory. Each line names an ad exchange, your account ID there, and whether the relationship is DIRECT or RESELLER. Buyers check it before they bid, so a complete, clean file protects your revenue.
What is the difference between DIRECT and RESELLER?
DIRECT means you hold the account with that exchange and sell through it yourself. RESELLER means you have authorised another company, such as an ad network, to sell your inventory through its own account. Most publishers need both, but more DIRECT paths make the supply chain shorter and cheaper and help avoid bidflation.
What are untracked ads.txt lines, and should I remove them?
Untracked lines are lines that none of your current demand partners need. Some are genuine lines for other partners you work with: add those as third-party requirements in your Fusion publisher settings so they are tracked. The rest are usually left over from old partners, and should be removed, because a dormant line lets a former partner keep reselling your inventory.
What happens if lines are missing from my ads.txt?
Buyers can't confirm that the exchange is allowed to sell your inventory, so they bid less or not at all, and you lose revenue. A missing supply-chain line, usually one with sid- in it, is flagged in Diagnostics as an incomplete supply chain. Ads.txt Insights lists every missing line so you can copy them in at once.
Does ads.txt have to be on the root domain, not www?
Yes. The IAB specification says crawlers look for the file on the root domain, such as https://example.com/ads.txt. A file that only exists at www.example.com/ads.txt, without a redirect from the root, won't be found. It also has to be served over HTTPS as text/plain, from the root folder.
How often does Fusion check my ads.txt?
Every 5 hours, so changes show up the same day. If you have updated your file and still don't see the change after 24 hours, email adops@contentignite.com.
What is app-ads.txt?
The app version of ads.txt. It lists who can sell your app's ad inventory and sits at the root of the developer website named in your App Store and Google Play listings. Give us that domain, add the lines we send you, and Fusion checks the file the same way. See app ad formats.
Can Content Ignite host my ads.txt for me?
Yes. Managed Ads.txt is a file we host for you, with your Content Ignite lines and any third-party lines you have entered in Fusion. Point your domain's ads.txt to it and it stays up to date as partners change. The link is in the Ads.txt requirements screen in Fusion.

Find out what your ads.txt is costing you.

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