Websites loading as mobile versions in Safari

This was driving me nuts - every time I went to a certain website on my MacBook, it displayed as if I was on a mobile... very frustrating. Anyway, I've managed to resolve it...

It appears that your MacBook may think you've zoomed in and it's kept the smaller area as the view. To reset it I just pressed Command 0 (or go to 'View > Actual Size') and it should appear like the usual desktop website view.

You're welcome! :)