Load tags only once per frame

  • This audit helps improve website performance by ensuring ad tag library scripts are only loaded once per frame.

  • Loading duplicate scripts can slow down page load times and negatively impact user experience.

  • Chrome DevTools' Network tab, with grouping by frame enabled, can be used to identify the source of duplicate ad tag scripts.

  • AdSense and Google Publisher Tag have specific scripts that should be monitored to ensure single loading instances.

Overview

This audit ensures that no frames load the same ad tag library script more than once. Including the same script multiple times is unnecessary and can lead to decreased page performance.

Recommendations

Remove duplicate ad tag library scripts. In some cases, duplicate scripts can be unknowingly loaded from two different locations. Examine where each duplicate script is coming from by reviewing network traffic and grouping requests by frame.

Identify the source of duplicate scripts

Use the Network tab in Chrome DevTools to determine which frame is loading duplicate scripts.

  1. Open DevTools by pressing Control+Shift+J or Command+Option+J (Mac).
  2. Navigate to the Network tab.
  3. If not already visible, click Filter The Filter icon to open the filter bar and select JS.
  4. Open Network Settings The Network Settings icon and select Group by frame.
  5. Reload the page to capture network traffic.

A screenshot of the Network tab in Chrome DevTools

More information

The following ad tag library scripts are supported:

Library Script(s)
AdSense

pagead2.googlesyndication.com/pagead/js/adsbygoogle.js

pagead2.googlesyndication.com/pagead/js/show_ads.js
Google Publisher Tag

googletagservices.com/tag/js/gpt.js

securepubads.g.doubleclick.net/tag/js/gpt.js