Emulate iPhone & iPad in Safari
To emulate an iPhone or iPad in Safari, you first need to have the developer tools enabled.
Then when visiting a page that you want to test, select “Develop” in the application toolbar then “Enter Responsive Design Mode”.
This will open a special window where you can emulate your website on an array of Apple devices and user agents.
To enter Responsive Design Mode without going through the toolbar, you can use the shortcut control command r.