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. Agent Analytics can track when it visits your website.
Category
Expected Behavior
AdsTxtCrawler behaves however its operator configured it, and scrapers as a category are the least polite bots on the web. Expect anything from slow careful extraction to rapid page hammering, robots.txt ignored, and user agent strings that change when blocked. Watch its volume and speed rather than trusting its label.
Overview
| Operated By | OneTag |
| Expected To Follow Robots.txt | Yes |
| Insights Last Updated | July 6, 2026 |
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
As of July 6, 2026, 0% of top websites block AdsTxtCrawler in their robots.txt files.
Overall Scraper Traffic
As of July 6, 2026, 0.5% of all web traffic came from scrapers.
Top Visited Website Categories
This data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the world's top 1000 websites and their robots.txt files.
AdsTxtCrawler's User Agent
| User Agent | Mozilla/5.0 (compatible; AdsTxtCrawler/1.0; +https://example.com/bot) |
Access other known user agents and IP addresses using the Enterprise API.
How To Block AdsTxtCrawler
Add this rule to your robots.txt file to block AdsTxtCrawler from accessing your entire website. You can customize which pages are blocked by swapping out / for a different path.
User-agent: AdsTxtCrawler # https://knownagents.com/agents/adstxtcrawler
Disallow: /Frequently Asked Questions
Should I Block AdsTxtCrawler?
Often yes. AdsTxtCrawler extracts content at scale, and scrapers in this category commonly republish or resell what they take. There is rarely an upside for the website being scraped, and copies of your content elsewhere can compete with your own pages in search. Almost none of the top websites we track have robots.txt rules for AdsTxtCrawler right now.
Does AdsTxtCrawler Respect Robots.txt?
Yes. AdsTxtCrawler is expected to honor robots.txt rules, so a disallow rule is the right first move. Automatic Robots.txt adds and maintains that rule for you, and Agent Analytics confirms AdsTxtCrawler actually honors it.
Does AdsTxtCrawler Access Private Content?
Assume AdsTxtCrawler will try. Scrapers routinely ignore robots.txt, and some go after paywalled or gated content when it has value. Real authentication stops most of them. Politeness conventions stop almost none of them.
Why Is AdsTxtCrawler Visiting My Website?
Your site has data AdsTxtCrawler's operator wants, like prices, listings, contact details, or articles. Scrapers target sites deliberately, so repeated visits mean your content specifically is the goal.
How Can I Tell if AdsTxtCrawler Is Visiting My Website?
Agent Analytics tracks AdsTxtCrawler visits in real time alongside every other known AI agent, crawler, and scraper. You can also check your server logs for requests whose user agent string contains "AdsTxtCrawler". Look for fast sequential requests across many pages. Keep in mind that AdsTxtCrawler doesn't publish a verification method, so any client can claim its user agent string and a log match is a hint rather than proof.