This Google Map web page works best on browsers that are “matchMedia” capable.
Here is a browser compatibility chart with a list of such browsers.
This Google Map web page is “mobile-friendly” down to a “320x480-pixels” screen-size. But, due to the nature of maps, the larger the screen this web page is viewed on, the better. Browsers that are not “matchMedia” capable (such as Internet Explorer 9) will not receive automatic “zoom-level” adjustments at smaller screen sizes to optimize the map’s appearance.