Off-Screen Detection

Off-screen ad detection

An ad can load, fire its impression, and charge you — while sitting off-screen where no human ever sees it. MediaSafe catches these hidden impressions without touching legitimate ads.

What off-screen fraud is

A page loads your banner, the impression pixel fires, the CPM is billed — but the ad was positioned where nobody could see it. A common trick: stack dozens of banners off-screen so every one shows and gets paid, while the user sees none. You pay for views that never happened.

Three forms

Off the viewport — the ad is placed far outside the visible area (e.g. left: -9999px).
Obscured — in the viewport but hidden under another element, or transparent (opacity: 0).
Zero visibility — visibility:hidden or display:none, so the slot renders and bills but is never shown.

How MediaSafe detects it

The impression pixel tracks the real position and visibility of the ad slot for the whole observation window. If the ad was never in view and sits off-screen or hidden the entire time, the impression is flagged as invalid (SIVT). The verdict is applied by our scoring worker, so measurement stays fast.

Built to be fair — three safeguards

1
Never double-counts
An off-screen impression is reported once, as off-screen — it does not also trigger the generic not-viewable signal. One clear reason, no inflated scores.
2
Lazy-load safe
We only flag an ad that stayed off-screen the entire window and was never once in view — a pre-loaded banner that later becomes visible is never flagged.
3
Publisher-side only
Detection runs on the publisher page where the slot position is knowable. Cross-domain creatives in isolated iframes are never mislabeled.

What we never flag

Legitimate ads in normal iframes, ads below the fold not yet scrolled to, and lazy-loaded banners that become visible — none are off-screen fraud, none are flagged.

How to enable

Install the impression pixel in publisher mode next to your ad slot. Off-screen detection runs automatically — results appear in the Impressions section of your dashboard.

<script src="https://ingest.mediasafe.cc/impression.js"
        data-site="as_YOUR_KEY" data-mode="publisher" async></script>

See the impression pixel guide or impression fraud detection.

Getting started

Add your site, grab the pixel, and off-screen detection is on — or reach us at support@mediasafe.cc.