In the early years of Internet Explorer development, Microsoft imbued its browser with proprietary features that differentiated it. The result was that many web developers created websites that relied on Internet Explorer's unique features to operate correctly. When these websites were visited with other browsers, there was no guarantee the site would look or act as intended.
Since that time, web standards promoted by the World Wide Web Consortium have become the gold standard for both browser development and website building. However, there are websites that were built initially to work best—or only—with Internet Explorer.
How to Use the Safari Develop Menu
Safari offers a hidden menu that provides a range of specialized tools and utilities used by web developers. Two of these tools can be helpful for misbehaving websites. However, before you can make use of these tools, you need to enable the Safari Develop menu in the Safari Preferences > Advanced screen. After you see Develop in the Safari menu bar, use the Safari User Agent command.
Safari allows you to specify the user-agent code that your computer sends to any website you visit. The user agent tells the website which browser you're using, and the site uses the user agent to decide if it can serve the web page correctly for you. If you encounter a website that remains blank, doesn't seem to load, or produces a message saying something along the lines of, "This website is best viewed with," then changing the Safari user agent may work.
From the Develop drop-down menu, select User Agent to open a list of available user agents that allow Safari to masquerade as Firefox, Google Chrome, Internet Explorer, or Microsoft Edge—or iPhone, iPad, and iPod touch versions of Safari.
Make a selection from the list, and the browser reloads the current page using the new user agent. Repeat the process with different user agents as needed.
Reset the user agent back to the Default (Automatically Chosen) setting when you're done visiting the website.