Quantcast Asynchronous Tag FAQ

See also the Web Measurement Implementation Guide.

What is the Quantcast asynchronous tag?
As part of the most widely-used direct measurement solution, the Quantcast asynchronous tag provides superior page loading performance. This tag is backwards compatible with the previous Quantcast JavaScript tag (see below) and supports all existing Quantcast services, such as audience segment labels.

How do I implement it?
For instructions, refer to the Web Measurement Implementation Guide.

Is it required?
Use of the Quantcast asynchronous tag is optional, but Quantcast recommends use of this tag instead of the previous tag. Quantcast continues to support the previous tag.

How does it work?
The Quantcast asynchronous tag ensures that the quant.js file (a core component of Quantcast Measurement) loads in the background. Furthermore, this file loads just once, on the first pageview per session. Upon subsequent pageviews, the Quantcast tag pushes notification of the pageview via the _qevents array.

How does it improve performance?
All this done in the background, which minimizes the number of direct calls, improves latency and ensures proper measurement. The result is that you continue to get Quantcast Measurement reporting with minimal impact on the end-user experience.

Is it backward compatible?
The tag is completely backwards compatible. If the quant.js loads, both the old and new tag will work fine, however, we recommend you use either the new or old tag on a single page, not both.

Will there be any impact on the traffic displayed on my Quantcast Profile after I switch to the asynchronous tag?
Assuming you simultaneously remove the old tag while adding the asynchronous tag, there will be no impact on your Quantcast reporting.

I have tags from multiple Quantcast accounts on my website. Will mixing and matching the async tag with the previous version of the tag cause any issues?
No. The asynchronous tag is fully compatible with the previous version of the tag.