The Recently Viewed and Recently Compared blocks usually appear in the right sidebar of a catalog page. The number of products listed in each can be configured for each website, store, or store view.
To configure recently viewed and compared products:
On the Admin sidebar, go to Stores > Settings > Configuration.
In the left panel, expand Catalog and choose Catalog underneath.
Expand the Recently Viewed/Compared Products section.
For a detailed description of each of these configuration settings, see Recently Viewed/Compared Products in the Configuration Reference Guide.
Set Synchronize widget products with backend storage to synchronize product widget information, such as product ID, with your current product storage availability in the database and reuse this information on different devices.
Set Show for Current to the website, store, or store view where the configuration applies.
For Default Recently Viewed Products Count, enter the number of recently viewed products to appear in the list.
For Default Recently Compared Products Count, enter the number of recently compared products to appear in the list.
For Lifetime of products in Recently Viewed Widget, enter any time range in seconds, greater than zero.
This setting determines how long the viewed products are shown in the recently viewed list.
For Lifetime of products in Recently Compared Widget, enter any time range in seconds, greater than zero.
This setting determines how long the compared products are shown in the recently compared list.
When complete, click Save Config.