Step 1.  Open Safari preferences by going to Safari → Preferences or using Command+, (that’s comma). Then click the ‘Advanced’ button and select the checkbox labeled "Show Develop menu in menu bar." See screenshot below.

Step 2. Close the Advanced window and go to the Develop menu, select User Agent and receive drop down menu of available browsers. See screenshot below Select the browser you wish to emulate. Note: The default setting returns once you close out Safari.

Step.3 Your screen will refresh, you are now emulating the browser you selected. Once you close out the window for Safari the User Agent will go back to the Default setting.