Note: If you are not already using Custom Variables to measure your custom data, we recommend to use the Custom Dimensions feature instead. There are many advantages of Custom Dimensions over Custom variables. Custom variables will be deprecated in the future.
Matomo (Piwik) custom variables tracking are an easy way to track custom values and variables about your visits (for example “Username”, “Membership level”) or page views (eg. “Category:Sport”). You can track up to 5 variables for each Visit on your website. On top of these 5 custom variables for each visit you can also track up to 5 custom variables for each page view.
Learn more about Custom Variables Analytics.