How to un-sync the browsing history on your iPhone from your iPad or other iDevices
How to unlink the Safari browser on your iPhone from your iPad or other iDevices
Safari auto-synchronises across devices. Here we have an iPhone and an iPad, both on the same iCloud account. Notice how the bookmarks are synced. The same goes for browsing history. Let's see how we can unlink the iPhone from the cloud:
1: Go into Settings
2: Tap on your Apple ID banner at the top of the menu
Once in there, turn off syncing with Safari. You will be asked whether you want to delete everything that has been synced to the cloud from Safari. This will basically get rid of your reading list, bookmarks, and favorites, but will not delete your browsing history. If you want that to happen, keep reading on to the next step.

That should be enough to keep your iPhone and iPad browsers separate. If you want to go the extra mile and clean any browsing history data on your current iDevice, proceed with the following steps:
1: From Settings, scroll down and tap on Safari2: Scroll down and find "Clear History and Website Data"
ncG1vNJzZmivp6x7sbTOp5yaqpWjrm%2BvzqZmp52nqHyJu9Zmq6hlpaN6tMXNnGStoJVir7O71qygp59dnba0wM6rsGannmLGsMHRZqCJoJ%2Bjsm6y0aikZrGfqr9uta%2Bam2anomK8tbTEq2SifJWrtqSx0pignW5pbYJy