What is IASCrawler?

IASCrawler is a bot in the advertising and marketing bots category, operated by Integral Ad Science.

Bot name
IASCrawler
Operator
Integral Ad Science
Type
Bot
Respects robots.txt
Not confirmed
robots.txt user agent
ias_crawler
Signs requests (Web Bot Auth)
No

About IASCrawler

Integral Ad Science (IAS) is the global market leader in digital ad verification, offering technologies that drive high-quality advertising media.

Advertising bots review landing pages, check ad placements and classify pages for brand safety and contextual targeting. Blocking ad verification bots can stop your ads or your inventory from serving, so allow the ones your ad partners use.

IASCrawler user agent

IASCrawler identifies itself with this user agent string:

  • IAS crawler (ias_crawler; http://integralads.com/site-indexing-policy/)

Anyone can copy a user agent string. Transfon Security also checks where each request comes from, so a request that claims to be a known crawler but comes from the wrong network is treated as a fake, not as the real crawler.

How to block IASCrawler in robots.txt

We have not confirmed whether IASCrawler follows robots.txt. Add a rule, then check your logs to see that it stopped. robots.txt is a plain text file at the root of your domain, such as https://example.com/robots.txt.

Block IASCrawler from the whole site

User-agent: ias_crawler
Disallow: /

Block IASCrawler from some folders

User-agent: ias_crawler
Disallow: /private/
Disallow: /search

Allow IASCrawler only on some folders

User-agent: ias_crawler
Allow: /blog/
Disallow: /

Allow IASCrawler and block other crawlers

User-agent: ias_crawler
Allow: /

User-agent: *
Disallow: /

Things to know

  • Each host needs its own file. Rules on www.example.com do not apply to shop.example.com.
  • A crawler obeys only the most specific group that names it. Once you add a User-agent: ias_crawler group, IASCrawler ignores your User-agent: * rules, so repeat any that should still apply.
  • The user agent name is not case sensitive. We take ias_crawler from IASCrawler's user agent; check Integral Ad Science's own documentation if it publishes a different robots.txt name.
  • Crawlers cache robots.txt, so changes can take up to a day to apply. Disallow stops crawling but does not remove pages already collected or indexed.

Limits of robots.txt

  1. IASCrawler may not follow the rule. robots.txt is a request that nothing enforces, and we have not confirmed that IASCrawler follows it. Check your logs after adding a rule.
  2. The user agent could be fake. robots.txt matches the name a request claims. Anyone can send IASCrawler's user agent, and a scraper using it is not bound by Integral Ad Science's robots.txt policy. Only checking the source network tells a real IASCrawler from a fake one.

Treat robots.txt as a statement of your policy, and enforce it where requests arrive.

Who should care about IASCrawler

Publishers

Ad verification and contextual crawlers like IASCrawler can decide whether your pages get demand. Blocking the ones your partners use can lower fill rates.

Transfon Security for publishers

Media buyers and advertisers

IASCrawler checks pages for ad platforms. Its visits to landing pages are not users, so exclude them from conversion data.

Transfon Security for advertisers

E-commerce

Ad platforms send crawlers like IASCrawler to check product landing pages. Keep it allowed so ads are not disapproved, and out of analytics.

Transfon Security for e-commerce

SaaS and APIs

Allow IASCrawler on landing pages linked from your ads, and keep it off the app.

Transfon Security for SaaS and APIs

Block IASCrawler with Transfon Security

robots.txt is a request, not an enforcement. Transfon Security shows IASCrawler by name in the Top Bots report, so you can see how often it visits and which pages it reads. Block or allow it with a User Agent rule, or slow it down with a rate limit decision rule.

Transfon Security

Control IASCrawler on your site

  • See every IASCrawler visit and the pages it reads
  • Spot bots that fake trusted crawler names
  • Block, allow or rate limit IASCrawler with one rule
  • Works with or without robots.txt support

Frequently asked questions

What is IASCrawler?

IASCrawler is a bot in the advertising and marketing bots category, operated by Integral Ad Science. Integral Ad Science (IAS) is the global market leader in digital ad verification, offering technologies that drive high-quality advertising media.

Does IASCrawler respect robots.txt?

We have not confirmed whether IASCrawler follows robots.txt. Add a robots.txt rule, then check your logs to see that it stopped, and block it by user agent if it did not.

How do I block IASCrawler?

Add "User-agent: ias_crawler" followed by "Disallow: /" to the robots.txt file at the root of your site. To enforce it, block requests whose user agent contains "ias_crawler" at your WAF. In Transfon Security that is one User Agent block rule.

Is robots.txt enough to block IASCrawler?

No. robots.txt is voluntary, so IASCrawler may not follow it, and anyone can send IASCrawler's user agent, so a fake IASCrawler ignores your rule. Enforce the rule where requests arrive, at your WAF, and check the source network.

Should I block IASCrawler?

Advertising bots review landing pages, check ad placements and classify pages for brand safety and contextual targeting. Blocking ad verification bots can stop your ads or your inventory from serving, so allow the ones your ad partners use.

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