I don't know ! How to check?
From Apple's knowledge base pages:
"To visit sites without making history, turn Private on or off in Safari.
To turn on private browsing, tap Safari, and then tap in the lower right corner. Tap Private to turn private browsing on.
This will protect your private information and block some websites from tracking your behavior. Safari won't remember the pages you visit, your search history, or your AutoFill information.
Note: While Private is enabled, Safari appears black or dark instead of white or gray."