Comparing basemaps side by side allows you to visually inspect change between two time periods.
Choose Basemaps for Comparison
To start comparing basemaps side by side, click on the Compare button on the lower right hand corner of the map. It is the second button from the top. From there, you will see a split screen. You can now select one basemap to inspect on the left side of the screen and another basemap to inspect on the right side of the screen.
You can find a list of your available basemaps in the menu on the left hand side. To compare basemaps, select a basemap from this list by clicking on it and drag it into the split screen.
You will see basemap's date listed at the bottom of each panel in the split screen.
Please Note: You can only compare basemaps for the same area.
Inspect and Zoom
Once you have selected the two basemaps you'd like to compare, you can zoom and pan around the basemap and both panels of the split screen will mirror your movements.
You can zoom either with your mouse or trackpad or by clicking the "+" and "-" buttons on the map.