What is Viewability?
A metric that measures whether an ad was actually visible to users, typically requiring 50% of the ad to be in view for at least one second.
Viewability is a digital advertising metric that determines whether an ad had the opportunity to be seen by users. According to industry standards set by the Media Rating Council (MRC) and IAB, a display ad is considered viewable when at least 50% of its pixels are visible in the viewport for a minimum of one second. For video ads, the requirement is 50% of pixels visible for at least two consecutive seconds.
Why It Matters
Viewability ensures advertisers pay for ads that users can actually see, improving campaign effectiveness and ROI. It helps combat ad fraud, provides better measurement of true ad exposure, and enables more accurate pricing models. Publishers benefit by demonstrating the quality of their ad inventory and can command premium rates for highly viewable placements.
How to Calculate
Viewability Rate = (Number of Viewable Impressions ÷ Total Measured Impressions) × 100%. For example, if 800 impressions out of 1,000 measured impressions meet viewability criteria, the viewability rate is 80%.
Industry Benchmarks
| Category | Average | Good Performance |
|---|---|---|
| Display Ads | 50-70% | 70%+ |
| Video Ads | 60-80% | 80%+ |
| Mobile Display | 40-60% | 60%+ |
Best Practices
Optimize ad placements above the fold for better viewability. Use lazy loading techniques to improve page performance while maintaining viewability. Monitor viewability rates by placement, device, and format. Implement viewability measurement from multiple vendors for accuracy. Focus on quality placements over quantity to achieve higher viewability rates.
Examples
A banner ad placed at the top of a mobile article achieves 85% viewability, while the same ad placed at the bottom only reaches 35%. A video ad that auto-plays when 50% visible maintains 90% viewability. An e-commerce site optimizes product page ad placements to achieve 75% average viewability.
Notes
Viewability measurement can vary between different tracking vendors due to methodology differences. The MRC viewability standard is widely adopted but some advertisers may set higher thresholds. Mobile viewability rates are typically lower than desktop due to smaller screen sizes and user behavior patterns.