How to use MAPfrappe…

First, in the left-hand map:

  1. Navigate to a place of interest. Use the map’s search box if needed.
  2. Click the map a few times to make an outline.

Next, in the right-hand map:

  1. Navigate to a different place of interest. Again, use the search box if needed.
  2. Move the map. Your outline floats over the map at the proper scale.

Share Your Map

Do you want to share this map?

Click the button below to generate a URL for this map. You can share the URL with your friends.

Generated URL:
(not requested yet) hidden initially


About MAPfrappe

Basic information

MAPfrappe shows you an outline of one part of the world overlaid on another part of the world.

You draw an outline in the left-hand map, and that outline is overlaid over the right-hand map at an appropriate size.

For example, you can sketch an outline of California in left-hand map; and you can see your outline overlaid over Italy in the other map. The outline in the left-hand map stays centered in the other map, and at an appropriate size.

You need basic knowledge of Google Maps interactions to get the most out of this web page.

Here’s how you can use this page…

1) Click on the left-hand map to draw an outline. Each click makes a new segment of the outline. Click on Close or End to finish one outline and start a new, disconnected outline. You can draw a closed outline (ClosedOutlineSample), or an open outline (OpenOutlineSample), or several outlines (MultiOutlineSample). An outline can have as many points as you want. But if you use a large number of points, your browser may redraw the image slowly.

2) As you draw your outline in the left-hand map, the outline appears at the center of the right-hand map. You can drag and zoom the right-hand map to anywhere in the world, and the outline stays in the center of the map. The outline keeps the same real-world size as in the left-hand map, so it may become very large or very tiny in the right-hand map.

You can use this page to answer questions like these: How big is Manhattan compared to my home town? How big is Texas compared to France? How big is the Golden Gate Bridge compared to my neighborhood?

Version 1.01. Last updated 11 Oct 2016.

Shape distortion

Your outline’s size or shape may change as you move around on the map. This distortion occurs for two different reasons.

First, Google Maps uses a Mercator projection for its maps. By design, this projection distorts distances at different latitudes. Distances are magnified at higher latitudes.

Second, my calculation of comparison marker positions attempts to preserve true distances between markers. These calculations account for the fact that units of longitude have different lengths depending on latitude. The calculations reverse Mercator distortions of horizontal distances.

Related sites

If you like this page, you might also like some of these:

  • Original MAPfrappe site - Original version of MAPfrappe, intended for desktop browsers.
  • Drew’s MAPfrappe index and blog - Drew is a fan of my site and maintains a publicly shared index of map comparisons. Thanks Drew!
  • The True Size - Interact with outlines of selected countries and U.S. states - supports rotation.
  • Gmap Pedometer - Draw a route or outline on a map, and the site tells you the length of the route. The site also lets you associate your route with a permanent URL.
  • ACME Planimeter - Draw an outline on a map, and the site tells you the area of the enclosed region.
  • Old SCTV Skit - SCTV did this long before I did.

Future work

User Interface Improvements

  • Improved callout of incompatible browsers.
  • Smaller header for narrow windows.
  • Shrink search box for narrow maps.
  • Fix control button highlight on some browsers.
  • Text on info pages should be selectable.
  • Nicer fail message for very small screens.
  • Desktop Safari: Window gets scrollbar when popup window is up.

Features and Bug Fixes

  • Experiment with more Android devices.
  • Get IE10 working again.
  • Tabbed interface to switch between the two maps.
  • Fix bugs at the International Date Line.
  • Rotation of reference objects.
  • Proper spherical geometry.
  • Auto-navigate button when the user gets lost.
  • User dragging of Comparison overlay.

What is “frappe”?

Frappé is the French word for “shaken.” It’s also a blended coffee beverage invented in Greece. Wikipedia discusses several uses of the word here.

People in the Boston area also refer to a milkshake as a “frappe.” They pronounce it “frap,” to rhyme with “map.” I invite visitors to pronounce “MAPfrappe” any way they like, but I pronounce it like the Boston folk, as “map-frap.”

History of this site

I created the earliest version of this site in 2006 to help me explore various geographic relationships. Since then, I've regularly updated the site for changes to Google Maps and various web browsers. However, the main site is not suited to mobile devices. Also the main site does not have a responsive, full-window interface expected of modern web applications.

In Summer 2014 I started updating the site with a new user interface for mobile browsers and improved user experience. This new interface is still a “beta” work-in-progress. I hope you can be patient with some awkward aspects of the new interface. I'm constantly working to improve it.

— Kelvin Thompson, January 2015


If you have some comments about this site, I would love to hear from you at this email address:

see image for email address

But I may change this address someday if it gets too much spam. Check back here for the latest address each time you want to write.


Map Examples