Chrome:
On your iPhone or iPad, open the Chrome app .
At the top-right, tap More .
Tap History. Clear browsing data.
Make sure that there's a tick mark next to 'Cookies, site data' and 'Cached images and files'.
Tap Clear browsing data.
Safari:
Here's how to clear information from your device:
To clear your history and cookies, go to Settings > Safari, and tap 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, go to Settings > Safari > Advanced > Website Data, then tap Remove All Website Data.