How can I customize sampling for page timing reports?

By default, 10% of all tracked events store information about the page performance. It is possible to customize it by adding a custom tag in the Tag Manager.

To increase the sample to 15% for example, follow these steps:

1. Open Piwik PRO.
2. Navigate to Menu > Tag Manager.
3. Click + Create new tag.
4. Name the tag.
5. Select Custom code (async) tag (custom asynchronous tag) and click Save.
6. Paste the following code:

   <script>
       var _paq = _paq || [];
       _paq.push(['setTimingDataSamplingOnPageLoad', 15]);
   </script>

   Note: In this code, you can change the number 15 to a different number to have a smaller or bigger sample. If you use 15 it means that 15% of the all tracked events will be measured to track the performance of pages.

7. Click + Existing trigger.
8. Pick the All page views trigger.
9. Click Save.
10. Click Publish. 

If you increase the sample to a much greater value than 15%, it will increase the number of tracking requests significantly and may cause performance problems in the tracking.