Open the Settings app
Tap Safari
Tap Clear History and Website Data
Tap Clear History and Data to confirm
To clear cookies for a specific site, tap Advanced
Tap Website Data
Swipe left on a website and tap Delete, or tap Remove All Website Data
If using Chrome, open Chrome
Tap the three dots menu
Tap History
Tap Clear Browsing Data
Select Cookies, Site Data
Tap Clear Browsing Data
Confirm the action