What is ad verification?
Ad verification is independent checking that ads ran as promised: served to real people rather than bots, in viewable positions, next to brand-safe content and in the right countries. Verification companies such as DoubleVerify and Integral Ad Science measure impressions with tags or SDKs, and can block bad placements before or after an ad is bought.
Ad verification typically covers invalid traffic, viewability, brand safety and suitability, and geography. Vendors seek MRC accreditation from the MRC for each metric. They sell to advertisers (to protect spend) and publishers (to prove quality).
In CTV and apps, measurement relies on the Open Measurement SDK or server-side signals, which are harder to verify than web browsers. The two biggest independent vendors changed shape recently: Novacap took IAS private in December 2025, while DoubleVerify remains public. Specialist fraud detection companies also focus on sophisticated IVT.