Matomo is slow! It takes a long time to load widgets, reports and pages FAQ - Troubleshooting

There are a few possible reasons that Matomo could be slow to load:

By default, Matomo processes reports when you request them in the user interface. Please see How to setup auto archiving of your reports every hour? to automate the generation of Matomo reports.
If you are using Matomo on one or multiple websites, tracking millions of pages daily, refer to How Matomo for high traffic websites.
If your server uses NFS-mounted storage (e.g., using OVH mutu webhost), widgets might load very slowly even if you are not tracking a lot of data. This is because Matomo by default uses “file based sessions” which are very slow when using NFS storage. The solution is to change a setting to enable Database session storage.