Here's how to clear information from your device:
To clear your history and cookies, tap Settings > Safari or Chrome > Clear History and Website Data. Clearing your history, cookies, and browsing data from Safari won't change your AutoFill information.
To clear your cookies and keep your history, tap Settings > Safari > Advanced > Website Data > Remove All Website Data.
When there's no history or website data to clear, the setting turns gray. The setting might also be gray if parental controls are set for websites.