Quantcast uses automated QA (quality assurance) technology to ensure advertisements we deliver meet Quantcast’s creative specifications. Advertisements are regularly and autonomously checked by Quantcast’s QA technology while being delivered to website visitors.

Quantcast’s QA technology uses a specific User Agent (referred to as Quantcastbot) in HTTP requests to allow third parties, such as adservers, analytics providers and webmasters, to distinguish these request from regular internet traffic. The request header used is given below:

User-Agent: Quantcastbot/1.0 (+

For adservers and analytics providers

Quantcast’s QA technology will trigger impression and click trackers while checking an advertisement. The HTTP requests generated will include the Quantcastbot User Agent, and you should discount these requests from impression and click counts as non-human traffic. You should not alter the behaviour of an advertisement when it is requested by the Quantcastbot User Agent.

For webmasters

The Quantcast’s QA technology will not access your website unless Quantcast is trafficking adverts that click through to your website. Advertisements are checked regularly, so you may see several visits from Quantcastbot while advertisements are being delivered. The bot will only visit the landing page of an advertisement; the bot does not crawl your website content. As the bot follows a click on an advertisement, it doesn’t obey the rules specified in your website’s robots.txt file. This is to ensure that the advertisement landing page meets our guidelines, in addition to the originating advertisement.

Verifying the Quantcastbot User Agent

You can verify if a request accessing your server really is Quantcastbot by checking if the originating IP is or This is useful if you are concerned that spammers are accessing your site while claiming to be Quantcastbot.