
These performance gains from clearing, however, may not always counteract the benefits provided by retaining data and cookies. Eliminating this information also helps protect your privacy, eliminating information about your past browsing sessions and eliminating those cookies which track your habits. If your iPhone is running out of room, clearing the data can also reclaim some space.

Since this is data against which the browser checks at the start of virtually every website visit, a large amount of data can decrease performance. As more and more browsing is performed through the iPhone, greater amounts of data are collected.

Some speed can be reclaimed in your iPhone performance by removing cookies and data. Advantages and Disadvantages of Clearing Cookies and Data
