Technology / Screenshots
DoubleVerify’s proprietary crawlers, known as Virtual Visitors, are able to capture and provide clients with actual screenshot records that provide evidence for incidences of non-compliance. All screenshots of incidents are automatically captured by the Virtual Visitors without any human interaction or modification. In order to capture screenshots of incidents, the Virtual Visitor renders the web page and then copies and saves the entire HTML for the page along with a visual capture of the incident and the date and time the screenshot was taken. The HTML source code and image are assigned an identification number that uniquely identifies them in the DoubleVerify system and reports allowing us to then match each screenshot with a particular advertiser in the DoubleVerify system. This rigorous methodology ensures that each screenshot is an accurate depiction of the exact impression taken in real-time.
Understanding Virtual Visitors
Virtual Visitors are unique to DoubleVerify and enable us to gather granular information on advertisement delivery such as page placement, competitive collision, and more. In addition, Virtual Visitors ensure higher see-through rates (STR), which in turn provides more comprehensive, accurate verification.
Virtual Visitors are advanced visual crawlers that render the page, analyze the HTML structure of that page, and take a screenshot of the entire page along with the advertising placement. Virtual Visitors execute all the code on the page (exactly like any humanly-used browser). The Virtual Visitors read the HTML and structure of a web page to understand where and what advertisements are running. As part of this process, the Virtual Visitors save a screen capture of the page along with the date and time of the visit so the recorded impression and incident are preserved for reporting and remediation purposes.
Our Virtual Visitors are IAB-compliant, meaning the crawlers identify themselves and don’t count as actual visitors by ad servers. DoubleVerify has dozens of crawling servers located around the globe. We crawl billions of web pages per month as we work to verify more than 40 billion impressions monthly. Our crawlers mimic a real world visitor by accessing sites from different locations and imitating different user behaviors.