Ads.txt & Robots.txt Tester

Fetch /ads.txt and /robots.txt from any host and flag empty or missing files

100% free. This tool needs our server to do the work, so what you submit is sent there, processed and then discarded - it is never stored.

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About this tool

Crawlers look at /robots.txt. Ad buyers look at /ads.txt (and often app-ads.txt). Both files must live at the host root, return a real document, and not be an empty 404 page. This tester fetches both for any domain, shows HTTP status, and prints the body or "(empty or missing)". It does not validate every ads.txt reseller line against an ad-tech spec. Use it when a site "is not being ads.txt crawled" or when Google Search Console complains about robots.

How to use this tool

  1. Enter the hostexample.com is enough. Paths are ignored; the tool requests /robots.txt and /ads.txt.
  2. TestTwo fetches, two status codes, two bodies.
  3. Fix at the rootA robots.txt in a subfolder is not the robots.txt. Same for ads.txt.

Common ads.txt and robots.txt mistakes

Both files must sit at the root of the host - example.com/ads.txt, not a subfolder - and return a real text file with a 200 status. A frequent problem is a site that returns its normal HTML page or a soft 404 for these paths, which crawlers and ad buyers read as broken.

Check both after any hosting move, CDN change or new subdomain, and after adding an ad network, whose seller line must appear in ads.txt.

Key features

  • robots.txt and ads.txt in one click.
  • Status code so a soft-404 HTML homepage is visible.
  • Raw body so a CMS login page posing as robots.txt is obvious.

Common uses

  • Confirming ads.txt exists before an ads.txt crawler visit.
  • Checking that robots.txt is not blocking Disallow: / by accident.
  • Seeing a 301 from apex to www that drops the file.

Tips for better results

  • ads.txt must be on the actual inventory domain, usually the apex that pages use.
  • robots.txt is not a security boundary. Sensitive URLs still need auth.
  • After upload, wait for caches. Re-test with a cache buster if a CDN is sticky.

Mistakes to avoid

  • Putting ads.txt on a blog subdomain when ads run on www.
  • Returning a 200 HTML "page not found" instead of 404. This tool will show that HTML.
  • Blocking the whole site in robots.txt and wondering why Googlebot left.

Frequently asked questions

After every site migration, CDN change or new ad partner, and whenever ad revenue drops without an obvious reason. A deploy that turns ads.txt into a redirect or an HTML error page can stop buyers bidding on your inventory, and a stray Disallow line in robots.txt can hide whole sections from search.

https://your-inventory-domain/ads.txt at the root, HTTPS, served as text. This tester requests exactly that path.

Empty is allowed but unusual. Missing (404) is also allowed and means "no extra rules". A 200 HTML error page is the bad case.

No. It fetches and shows the file. Line-level IAB ads.txt syntax is on you or your ad server.

Yes. Webmaster check, not an ads.txt crawler account.