What is AdsTxtCrawler?
AdsTxtCrawler is a bot operated by OneTag that crawls and retrieves ads.txt files from websites. These files are part of an Interactive Advertising Bureau standard that publishers use to publicly declare which companies are authorized to sell their advertising inventory in programmatic advertising. You can set up Agent Analytics to see when AdsTxtCrawler visits your website.
Overview
| Operated By | OneTag |
| Source | Official Website |
| Expected To Follow Robots.txt | Yes |
| Insights Last Updated | September 14, 2026 |
Do you operate this agent? Contact us to suggest an update.
Category
Expected Behavior
AdsTxtCrawler behaves according to its operator's configuration, and scrapers are among the least predictable bots on the web. It may range from slow, careful extraction to rapid, aggressive fetching, ignore robots.txt, or change its user-agent string when blocked. Its request volume and speed are more informative than its label.
AdsTxtCrawler's User Agent
| User Agent | AdsTxtCrawler/1.0 |
How To Block AdsTxtCrawler With Robots.txt
Add this rule to your robots.txt file to block AdsTxtCrawler from accessing your website, or use Automatic Robots.txt to block all scrapers at once. You can customize which pages are blocked by swapping out / for a different path.
User-agent: AdsTxtCrawler # https://knownagents.com/agents/adstxtcrawler
Disallow: /Insights for AdsTxtCrawler
As of September 14, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the top 1000 websites and their robots.txt files.
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
6% of top websites block AdsTxtCrawler in their robots.txts.
Overall Scraper Traffic
0.1% of all web traffic came from scrapers.
Top Visited Website Categories
The types of websites most frequently visited by AdsTxtCrawler.
Frequently Asked Questions
Should I Block AdsTxtCrawler?
Often. AdsTxtCrawler collects content at scale, and scrapers in this category may republish or resell it. The site being scraped rarely benefits, while duplicate copies can compete with its pages in search results. For context, 6% of the top websites we track currently have robots.txt rules for AdsTxtCrawler.
Does AdsTxtCrawler Follow Robots.txt Rules?
Yes. AdsTxtCrawler is expected to follow robots.txt rules, so a disallow rule is the appropriate first step. Automatic Robots.txt can add and maintain that rule, while Agent Analytics lets you verify whether AdsTxtCrawler respects it.
Does AdsTxtCrawler Access Private Content?
It may try. Scrapers often ignore robots.txt, and some attempt to collect valuable paywalled or gated content. Authentication is the strongest protection; robots.txt alone does not restrict access.
How Can I Tell if AdsTxtCrawler Is Visiting My Website?
Agent Analytics tracks AdsTxtCrawler visits in real time. You can also check your server logs for requests whose user-agent string contains "AdsTxtCrawler". Look for rapid, sequential requests across many pages. Because AdsTxtCrawler does not publish a verification method, any client can claim its identity and a log match is only a clue.
Why Is AdsTxtCrawler Visiting My Website?
Your site contains data AdsTxtCrawler's operator wants, such as prices, listings, contact details, or articles. Repeated visits generally indicate that your content remains a collection target.