Find out why an ad slot is empty

When an ad slot on your website appears blank, guessing the cause is unnecessary. The AdServeKit ad delivery tag (ad.js) includes a built-in visual diagnostic tool that inspects live ad requests on your page.

To open the debugger, append ?adserve_debug=1 to the URL of any page on your website containing an ad slot (for example, https://example.com/article?adserve_debug=1). If the URL already contains a query string, append &adserve_debug=1.

The floating AdServeKit Debugger bar will appear over your page, outlining every house-ad-slot container with a diagnostic border. The tool is safe to use on live production pages and is visible only in your browser tab.

Click on any ad slot in the debugger overlay to view its delivery diagnostic report:

- SUCCESS / SERVED: An ad was selected, delivered, and rendered in the slot.

- NO_ELIGIBLE_CAMPAIGN: No active campaign is targeting this placement or website. Confirm that a campaign targeting this placement is set to Active in your dashboard.

- SIZE_MISMATCH: A campaign is active, but none of its attached creatives match the slot dimensions. Open Creatives, add the missing dimension variant, and Publish Revision.

- OUTSIDE_SCHEDULE: The campaign start date is in the future, the end date has passed, or the current time is excluded by dayparting. Check flight dates and timezone settings.

- BUDGET_EXHAUSTED: The campaign has reached its daily budget cap or total lifetime budget. Increase the budget limit or wait for the midnight reset.

- FREQUENCY_CAPPED: The campaign is active, but your browser has reached the maximum allowed impressions for the configured time window. Test in an Incognito window.

- DOMAIN_UNVERIFIED / INVALID_DELIVERY: The request origin domain does not match an authorized, verified domain on the website record. Add the hostname under Authorized Domains.

- GEO_TARGETING_EXCLUDED: Your current IP country is excluded by the campaign geographic rules.

- DEVICE_TARGETING_EXCLUDED: Your current device (mobile, desktop, tablet) is excluded by campaign settings.

A common concern for publishers is why total pageviews in Google Analytics do not match rendered ad impressions in AdServeKit. This discrepancy is standard in digital advertising:

- Lazy Loading: Slots below the fold only request an ad when the user scrolls near them. Visitors who exit before scrolling generate a pageview but zero ad requests.

- Content Blockers: Privacy extensions and ad-blocking browsers block ad.js from loading, stopping the ad request before it reaches the server.

- No-Fill Events: If a placement has no active campaign or fallback creative matching its dimensions, an ad request occurs but no impression renders.

- Rapid Bounces: Visitors who close the tab before the creative finishes rendering never trigger an impression confirmation beacon.

- Viewability Standards: A rendered impression confirms the ad was drawn; a viewable impression requires at least 50% of the ad area to remain visible on screen for at least 1 continuous second.

If appending ?adserve_debug=1 does not display the debugger overlay:

1. Confirm that ad.js is loaded in the page source: View source and ensure <script async src="https://api.adservekit.com/ad.js"></script> is present.

2. Check for ad blockers: Disable browser extensions that block script execution.

3. Check Content Security Policy (CSP): If your web server emits a restrictive CSP header, ensure api.adservekit.com is allowed in script-src and connect-src directives.