Site Speed Sample Rate in Google Analytics remains at 25%

Question

I defined a Site Speed Sample Rate of 100% (via the Google Tag Manager). It's definitely more than 1% now but far from 100%. In fact a comparison of the speed samples and real pageviews in GA shows, that the rate is at constant 25% now. Our page has about 10,0000 users per day. Every page includes the same simple tag.

Any ideas what could be wrong? Thanks!

Answer 1

Site speed hits are sampled on the server as well as the client. You may be running into the limits outlined here:
https://developers.google.com/analytics/devguides/collection/analyticsjs/user-timings#sampling

In fact a comparison of the speed samples and real pageviews in GA shows, that the rate is at constant 25% now.

I'm not sure how you're coming to this conclusion. I don't think there's any reliable way to know what percentage of hits were sent from looking at reports.

The best way to test whether 100% of hits are being sent is to inspect the network tab in your browser's developer tools. If you set siteSpeedSampleRate to 100 , you should be able to clear your cookies, refresh the page, and see timing hits being sent. If you repeat this (making sure to clear cookies), you should see hits being sent 100% of the time.

Answer 2

Although setting siteSpeedSampleRate to 100 will indeed send speed data every time, you might be hitting one of the site speed processing quotas:

• https://developers.google.com/analytics/devguides/collection/analyticsjs/limits-quotas#timing_hits
• https://developers.google.com/analytics/devguides/collection/analyticsjs/user-timings#sampling_considerations