How do I read the result?
Enter a domain or any page address on the site, then press Check site. The sentence under the site's name gives the answer: who runs its ads, who else can sell its ad space, and when we last confirmed them live.
Those words follow how we confirmed each network. A network is the site's main ad network, and the sentence says the site runs it, only when a MANAGERDOMAIN line in its ads.txt names it. For other networks in the file, the sentence says the file lets them sell its ad space, because a listing alone doesn't show which one is in charge. When we confirmed a network from the ad code on the site's pages instead, the sentence says that and doesn't claim the ads.txt file names it.
The row of facts under it describes the site: main ad network, traffic, niche, platform, the year its domain was registered, and its publisher. Each fact shows only when we know it, so a site we know little about has a short row. The same goes for the sections below it.
What do the statuses in the networks table mean?
The table lists every network we've linked to the site, including ones that stopped. What its ads.txt says shows whether the file names the network as an ad manager or allows it to sell ad space. It says Not listed when we confirmed the network from the site's page ad code, or when we don't know how we confirmed it. Since is the month we first confirmed it.
| Status | What it means |
|---|---|
| Confirmed live | Our last check found the network on the site. |
| Not seen lately | Two checks at least 48 hours apart didn't find it. It may come back. |
| Ended, with a month | Three checks over seven days or more didn't find it. The month is when it ended. |
What do the other sections show?
| Section | What it shows |
|---|---|
| How have its ad networks changed? | One bar per network, from the month it first appeared to the month it last did, and a list of each change, newest first. It says a site moved from one network to another only when one ad manager replaced another within seven days. The section shows once a site has a real change, such as a network that left. |
| What is in its ads.txt file? | How many lines, companies, direct lines, and reseller lines the file has, the companies with the most lines, and the start of the file. |
| Similar sites | Other sites on the same main ad network, or on the same networks when there's no MANAGERDOMAIN line. Click one to check it here. |
A food blog with one ad network can still list dozens of companies in its ads.txt, because the network brings its own partners. The companies with the most lines are usually those partners, not separate networks.
collegefashion.net
Example
Its ads.txt has the line MANAGERDOMAIN=mediavine.com, so the sentence reads collegefashion.net runs Mediavine, and its ads.txt file names Mediavine as its ad manager. Mediavine is its main ad network and shows as Confirmed live in the networks table.
Use Copy link to share the result. The link opens this page and checks the same site.
What can I do with the result?
It depends on why you're checking:
| If you're | Look at |
|---|---|
| Choosing a network | Check a few sites in your niche that are a little bigger than yours. If they run the same network, open its page in the ad networks directory to see what it takes to join and how it pays. Similar sites shows more sites on that network. |
| Checking your own site | After you join a network, check that its MANAGERDOMAIN line or seller lines show here. If a network you left still shows, its lines are probably still in your ads.txt file. |
| Buying a site | See which networks it runs and how that changed over time. A recent switch is worth asking the seller about. |
How do I find out which ad network a website uses?
Open the site's ads.txt file by adding /ads.txt to its address, such as example.com/ads.txt. Look for a line that starts with MANAGERDOMAIN. If it's there, it names the company that manages the site's ads.
Without that line, the file is a list of companies allowed to sell the site's ad space. Spotting the network in that list takes practice, because most lines belong to the network's partners. This checker does that reading for you and matches the lines to the networks we track.
You can also look at the page's code for ad scripts, but scripts change often and some load only for certain visitors. The ads.txt file is public, stable, and written by the site owner, so we rely on it.
What does MANAGERDOMAIN mean in ads.txt?
MANAGERDOMAIN names the primary or exclusive company that sells a site's ad space, as defined in the IAB ads.txt 1.1 spec. Most of the network links we confirm come from this line.
It doesn't prove the deal is exclusive. A site can name a manager and still let other networks sell its ad space, which is why the result can show one main ad network and still list others.
OWNERDOMAIN is a different line. It names the business that owns the site, not an ad network.
Why does the ads.txt file list so many companies?
Each line authorizes one ad account to sell the site's space. DIRECT means the site's own account with that company. RESELLER means a company that sells the space on someone else's behalf, usually the site's ad network.
A network such as Mediavine works with dozens of ad exchanges, and each one needs its own line. That's why one network can add dozens of lines. The IAB's ads.txt page explains the format in full.
How do I set up ads.txt on my own site?
Put a plain text file named ads.txt at the root of your domain, so it opens at yoursite.com/ads.txt. Your ad network gives you the lines to add. Each line has up to four parts:
google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0| Part | What it is |
|---|---|
google.com | The ad system that sells your space. |
pub-0000000000000000 | Your account ID with that ad system. |
DIRECT | You hold the account yourself. RESELLER means a partner sells on your behalf. |
f08c47fec0942fa0 | Optional. The ad system's ID with the Trustworthy Accountability Group. |
Ad buyers use this file to check who may sell your space, and they can skip sellers it doesn't list. When you switch networks, replace the old network's lines with the new ones.
Why isn't a site in the results?
We only show sites our checker has read. We find sites from public lists and each network's own seller list, then read their ads.txt on a schedule. A new or small site may not be in our list yet.
A site also stays out when we can't confirm a network we track. That includes most sites with no ads.txt file (a few networks can be confirmed from homepage ad code alone), sites that block our checker, and sites that use a network outside our list. The ad networks directory lists every network we track.
How current is the result?
The Checked date under the site name is our latest read of its ads.txt. We recheck sites on a schedule.
The Since month is when we first confirmed a network. If that was our first check of the site, the network may have been there for years before. The changes section says when our checks of the site started.
One missed check never removes a network. A timeout or a blocked request counts as unknown. A network moves to Not seen lately, then Ended, only after repeated checks find it missing.
What does the traffic group mean?
It's the site's place in Google's list of the million most visited sites by Chrome users: top 10k, top 100k, or top 1M. Not ranked means the site wasn't in this month's list. That doesn't mean zero traffic: the list only covers sites with enough Chrome visitors.
We don't show visit counts or estimate earnings, because there's no public source we can check them against.