Calculating unique visitor numbers can be resource-intensive, especially over extended periods, which may increase the time needed to archive A/B test reports. To mitigate this, Matomo now supports the use of HyperLogLog to calculate estimated unique visitors. For a more detailed explanation of HyperLogLog and estimated unique visitors in A/B testing, refer to this FAQ.

To enable HyperLogLog, update your configuration file located at config/config.ini.php with the following code:

[AbTesting]
enableEstimatedUniqueVisitors = 1
show_estimated_unique_visitors = 1
archive_unique_visitors_enabled = 0
show_unique_visitors = 0

Note: Adding the above configuration will enable a new metric in your reports called “Estimated Unique Visitors” and disable the “Unique Visitors” metric.

Previous FAQ: Does the A/B testing framework add a lot of data to the Matomo JavaScript tracker?