How to: Use the Develop menu
1 Turn it on
If a site claims you need another browser or device to use it, the Develop menu may enable you to circumvent the roadblock. Activate it in the Advanced section of Safari’s preferences (check ‘Show Develop menu in menu bar’).
2 Switch browsers
If you’ve installed another browser, it will be listed in Develop > Open Page With, alongside Safari. Select the browser and the current web page will be sent to it. Note that login details won’t go along for the ride.
3 Spoof a browser
Go to Develop > User Agent to have Safari pretend to be another browser. This is useful for when a mobile version of a site will play video, but the desktop version still requires you to install Flash, like you’re living in 2005.