"Unique visitors" are more than "Visits"


There wasn’t a specific answer to this issue so posting a new thread.

Please refer attached images.

Question1: How can we have more unique visitors than visits in a specific time period?
Question 2: When we ran Report1 for Oct. 21 – Dec.19 we get 180,645 Visits and 157,619 Unique Visits.

If we run a Report2 from Oct. 21 – Dec.31 we get: 276,956 Visitors164,257 Unique Visitors
If we run a Report for Dec. 20 – Dec.31 we get only: 4,220 Visitors and 7,777 Unique Visitors

• There should be 96,311 visitors for the period of Dec 20 – Dec 31 to make up for the difference between reports 1 and 2 above.
• This inconsistencies repeat for referrals as well.

Will appreciate a quick advice, if it is not a known issue with Piwik. We are using Piwik Version 2.0. Running Piwik since last 3 years and well pleased, until this time.


(Matthieu Aubry) #2

There seems to be an issue indeed.

Can you reproduce this bug on the Demo ? if you can, please post URLs of these reports.


I sometimes experience the very same problem on several of my websites tracked using Piwik.

It may be linked with 301 Moved Permanently and sum_daily_nb_uniq_visitors calculations incorrect for some ranges in many API methods · Issue #4377 · matomo-org/matomo · GitHub .

The workaround I use to fix the problem when I see it on a specific period, is to run an “invalidateArchivedReports” operation:


and then re-launch archive.php:

sudo -u apache php /…/misc/cron/archive.php --url=http://… --force-all-websites --force-all-periods