I have seen a few 404 errors when ads.txt is requested on some of the sites that I manage. I Guess the answer may be identical to the question about an empty robots.txt file or no file at all (just prevent some 404 errors). However I'm having dificuilty to understand the underlying concepts behind ads.txt.

The official help page at IAB is confusing, for example

"When a brand advertiser buys media programmatically, they rely on the fact that the URLs they purchase were legitimately sold by those publishers."

"advertisers buy media" sounds like hiring an atrist to make compelling text, graphics and animations, but does not fit with the context (it's unlikely one would hire artists programatically). "URLs sold by publishers" does not look like they are talking about registering an URL at an isp or ICANN. Publishers generally don't sell URLs unless they quit publishing.

Obviously this is a foreign domain specific language. So could anyone explain what impact an empty ads.txt file could have? Some concerns would be:

  • Would it in any way impact incoming links that look like they come from advertisements?
  • Would it have any impact on outgoing links to products or services mentioned in the content?
  • Would it render my site less interesting for indexing spiders or other crawlers?
  • Google Adsense sent me an email saying I should create such a file for my site, but I couldn't figure out what that file would actually do or how it would help my site. I'd sure like an easy to understand explanation of ads.txt. Commented Sep 17, 2018 at 1:34

3 Answers 3



According to version 1.0.2 of the ads.txt specification:


Some publishers may choose to not authorize any advertising system by publishing an empty ads.txt file, indicating that no advertising system is authorized to buy and sell ads on the website. So that consuming systems properly read and interpret the empty file (differentiating between web servers returning error pages for the /ads.txt URL), at least one properly formatted line must be included which adheres to the format specification described above. For files that do not otherwise contain authorized advertising system records, use the following "placeholder" record to indicate that the file adheres to the ads.txt specification:

placeholder.example.com, placeholder, DIRECT, placeholder

In other words, create ads.txt with the exact contents shown above.

Update October 2020:

Prior versions of the ads.txt specification indicated that publishers may simply use an empty ads.txt file to indicate that no advertising system is authorized to buy or sell ads on the website. That method is now deprecated because of ambiguities it creates and should be ignored by consuming systems after March 1, 2020.

  • 2
    So you're saying I use this line in an ads.txt file as is, with the words placeholder ?
    – blissweb
    Commented Jan 9, 2022 at 2:02
  • 2
    Yep, that's exactly right. Commented Jan 9, 2022 at 21:54

Ads.txt has zero to do with SEO or even UX. It is specific to programmatic advertising. It might be of interest if your websites display ads that are purchased on real time bidding (RTB) exchanges. Otherwise, you don't need this file.

Ads.txt also doesn't share anything in common with robots.txt, other than also being a plain text file, and generally getting placed at root level of the website.

I have never had to generate this file myself yet, since I work on the advertiser side these days, but as ads.txt has experienced wide adoption, I can share a little background. Essentially, when advertisers run ads on websites, they want to ensure that the website is what it claims to be. Bad actors have learned to spoof real, reputable websites on the exchanges and steal ad impressions, thus wasting advertiser dollars on impressions appearing on crappy websites or ones that humans may never even see.

The ads.txt initiative was a move to correct this. An ads.txt file will list all the exchanges that the publisher has a relationship with. Advertisers looking to buy an ad impression can crawl this file programmatically and check for the exchange to see if the site is legitimately a part of this exchange. Of course, bad actors have already found ways to sometimes get around this, in certain cases, but generally, these files make fraud more difficult.

Here's a pretty good guide, containing a link to Business Insider's file:


An empty ads.txt file will thus not benefit you, and not having one won't harm you, unless your websites sell ad impressions, in which case you might want to look into this. If you don't implement this file, you will still be able to sell ad impressions, since many advertisers buy through exchanges and networks that aren't thorough or strict. But if you're competing for top quality ads (and their ad dollars), check out the link above for implementation specifics.

  • I can relate to the fraud problem. After receiving free adwords credit, a large portion was swallowed up in a very short period, all on a "children's coloring pages download site"... Any way, the linked article is full of jargon like "advertising inventory" and "advertising media". I guess the file just confirms that a specific advertising account really belongs to the owner of a specific domain. But it leaves me wondering why GoogleBot is checking for this file every single day while I'm not running any ads at all. If I'm not running ads, then there would be nothing for them to confirm right? Commented Sep 17, 2018 at 23:21
  • @LouisSomers Honestly, this is the first I hear of Googlebot specifically requesting this file from a site, if the site isn't displaying ads. Google was one of the reasons for the rapid adoption of the ads.txt standard, so they may be trying to push for it. Also, chances are, you may have some Google Doubleclick or other code somewhere, bundled in with other Google Apps, that's making requests on your website; use Tag Assistant or Ghostery to see if any advertising tags live somewhere on your site. Commented Sep 18, 2018 at 3:52
  • @HenryVisotski My sites don't display adds but crawlers seem to look for the presence of a ads.txt fiel and thus it shows up as a 404 in our redirection logs. Commented May 3, 2019 at 8:10
  • 1
    @AndrewTruckle A few ways to deal with it. 1) Make sure your installation doesn't include some default ads.txt at the root that came with your CMS. 2) Make sure you don't have scripts on your site that may be making erroneous ad calls. DevTools or Ghostery are good at this. 3) Disallow the ads.txt in your robots.txt for all bots, as if it existed. 4) Place a blank ads.txt at your root. (There may be more ways to deal with it, these are a few I know to be effective.) Commented May 3, 2019 at 15:10

I think this is an idiotic behavior of Google. I have seen same 404 errors for websites which has no ads on them at Google Search Console.

This might be marketing method for Google for increasing Google Adsense publishers. I don’t know. In engineering point of view, simply it’s very stupid error to show 404 for websites which has no ads on them.

Solution is simply block bot access to the file on your robots.txt file by adding this line

Disallow: /ads.txt

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.