--- title: "What is viewability? | daily.dev Ads glossary" url: https://business.daily.dev/glossary/viewability/ description: "Viewability is whether an ad was on screen: at least half of it visible for at least one second. It separates impressions that reached a screen from ones served off it, and says nothing about whether anyone looked." lastUpdated: "2026-10-20" llmsTxt: https://business.daily.dev/llms.txt --- ## What is viewability? Viewability is whether an ad was on screen: at least half of it visible for at least one second. It separates impressions that reached a screen from ones served off it, and says nothing about whether anyone looked. Also called: Viewable impressions, Attention metrics. An impression is counted when an ad is served, including below the fold and in tabs no one is looking at. The viewability standard (half the ad, one second, two seconds for video) was introduced so buyers could stop paying for ads that never reached a screen. Most platforms now report viewable impressions alongside served ones. Viewable is still a low bar. Attention research measures eye movement and finds that 35% of "viewable" ads are actually looked at (Lumen / Adelaide attention research). A banner can be technically viewable in the corner of a page a reader is ignoring. The question that matters is whether the format gets looked at. Native placements change the answer. A card inside a feed is read as part of the feed; a newsletter slot is read as part of the issue. That is why developer campaigns are better judged on reads, follows and what happened next than on viewability alone. ## How is viewability measured? A verification script on the page checks whether the ad's pixels are within the browser viewport and for how long. The standard most buyers use: at least half of a display ad in view for one continuous second, half of a video ad for two seconds. Impressions that meet it are "viewable"; the share that do is the viewable rate. Platforms report it themselves or through third-party verification vendors. Ads below the fold, in background tabs, in collapsed sections or in windows the reader minimised are served but not viewable. On many pages that is most of them, which is why the standard exists. ## Why is viewable not the same as seen? Because the standard measures the screen, not the eyes. Eye-tracking and attention studies find that 35% of "viewable" ads are actually looked at (Lumen / Adelaide attention research): a banner can be fully on screen while the reader looks at the article beside it, and developers have spent years learning to look past anything banner-shaped. Viewability removes the impressions that never had a chance; it says nothing about the ones that had a chance and were ignored. ## How should a developer campaign use viewability? As a floor. Ask any platform for its viewable rate and treat a low one as a disqualifier. Then judge the campaign on measures that imply attention: reads to the end, upvotes and comments, follows on the company page, clicks, and conversions with a weeks-long window. A native card in a feed is viewable the way the posts around it are viewable; what matters is that it is read the way they are read. When comparing channels, put viewable rate, engagement and cost per activated developer side by side. A display network with a high viewable rate and no engagement is delivering ads to screens nobody is looking at. ## What should you ask a platform about viewability? - **What is the viewable rate,** and who measures it? - **Is it reported per placement,** so you can see which ones reach a screen? - **Do you bill on served or viewable impressions?** - **What do you report beyond viewability:** reads, engagement, conversions? A platform that only reports viewability is telling you the ad reached a screen. A platform that reports reads is telling you it reached a person. **Common mistakes** - Treating a high viewable rate as proof of attention. - Buying on served impressions when viewable ones are available. - Comparing viewable rates across formats that are read differently. - Reporting viewability to a team that should be hearing reads and follows. **How developers experience it** - A banner on screen is still a banner they learned to ignore. - A card in the feed is read because it is in the reading path. - They never think about viewability; they think about whether the post was worth it. ## On daily.dev daily.dev reports what viewability cannot: reads, upvotes, follows and the conversions your [conversion pixel](https://business.daily.dev/pixel.md) records, because [In-Feed Ads](https://business.daily.dev/feed.md) are read like the posts around them rather than measured for being on screen. ## Served, viewable, seen | | Served impression | Viewable impression | Seen | | --- | --- | --- | --- | | **Means** | The ad was delivered to the page | Half of it was on screen for a second | Someone looked at it | | **Counted by** | The ad server | Verification vendors | Attention and eye-tracking research | | **Proves** | Delivery | Opportunity to see | Attention | | **For developer campaigns** | A floor, not a result | Necessary, not sufficient | What reads, follows and conversions stand in for | ## Go deeper - [Native ads for developers: do they work?](https://business.daily.dev/resources/native-ads-developers-do-they-work.md) - [How developers experience ads](https://business.daily.dev/resources/how-developers-experience-affects-ad-engagement.md) Related terms: [Developer engagement](https://business.daily.dev/glossary/developer-engagement.md) | [Native advertising](https://business.daily.dev/glossary/native-advertising.md) | [Ad blocker](https://business.daily.dev/glossary/ad-blocker.md) ### Frequently asked questions **What is the viewability standard?** At least 50% of the ad's pixels in view for at least one continuous second for display, two seconds for video. Platforms and verification vendors report the share of impressions that met it. **Does viewable mean seen?** No. Viewable means the ad was on screen; seen means someone looked at it. Attention studies find that most viewable ads are not looked at, which is why native, in-content formats outperform banners for the same viewability. **What is a good viewable rate?** Higher than the average for the format, and reported per placement. Treat it as a floor to clear, then judge the campaign on engagement and conversions. **Should I buy on viewable impressions?** Where a platform offers it, yes, over served impressions. Better still, buy on a unit closer to attention: reads, or a managed plan reported on engagement. **How does daily.dev report viewability?** The weekly report leads with reads, upvotes, follows and pixel conversions, because a promoted post in the feed is read like the posts around it. Delivery numbers are there as context, not as the result. 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