Improvements to Google Mapping Site

This past weekend, I made several improvements to my site that allows you to map multiple locations on Google Maps. These improvements were mostly suggested by users of the site, and there were a couple that I came up with after seeing the usage patterns of the site, and trying to improve performance.

Read on to see the listing of new/improved features:


  • Added annotations to locations You can now include text at the end of each address line that is surrounded in curly-braces ({ and }), and that text will be displayed in the address bubble, and also in the listing below the map. For example, you could enter:

    123 Sesame St. New York, NY {Big Bird lives here}

  • Saved maps You can give your map a nick name, and you will be able to link to it at I noticed that a lot of people are using the service and linking to it from their page. THis will make it easier to link so you don’t have a ridiculously long url.

  • Cached Geocoding Results The service works by asking Google for the latitude and longitude of each address in the request. These coordinates are then used to plot the map. Before this update, we were asking Google for each address, every time. Now, we store the results the first time an address is mapped, and we will never ask Google for that address again.

  • Throttled Geocode Requests Google has restrictions on the number of addresses you can lookup at a time. This caused problems if you wanted to plot large numbers of addresses on this service. Some of the address would come back as unknown. Now, the service will pause briefly if it is looking up a large number of addresses that it doesn’t have stored in the cache. So, if you want to plot 100 addresses, it should work fine. You will notice that the first time, it may take a while for the map to show up. However, if you save the map, it will load quickly next time, since the addresses will be stored in the cache, and we don’t have to ask Google for them.

  • Category on this blog I have created a category on this blog for I will post announcements all updates on this site, so you can check back there, or subscribe to the RSS feed to be kept up to date.

So, I hope you find these improvements useful, and take a look at Please let me know what you think in the comments, or via email at

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  1. Posted June 17, 2009 at 5:16 pm | Permalink

    Greate Tool. I am looking at trying to have an onclick event that can return the click position gps coordinates on the goolge map to the window.openner.

    I have a button on my website that opens the google maps webpage at a specific GPS Co-Ordinates the it determines from an address lookup using th google API. This may not be exactly accurate, so I want the user to be able to click on the exact position on the map and have it return the co ordinates of that position back to the oppener window so those can be used to update the address.

    Any Ideas on this solution or if it’s even possisble ?


  2. Posted June 18, 2009 at 2:46 pm | Permalink

    Hi Dale

    You should check out the Google Maps API V3 (which is still in Google Labs). I haven’t played with it yet, but it looks like it makes this pretty easy.

    The Map class has events for click, double click, and right click, which all pass a MouseEvent as a parameter. That MouseEvent should have the coordinates you are after.

  3. Posted August 25, 2009 at 9:14 am | Permalink

    You might find this interesting:
    Google I/O 2009 – Performance Tips for Geo API Mashups

  4. Ana Arellano
    Posted February 23, 2010 at 6:36 pm | Permalink

    Hi, Patrick, I was mapping members of my non-profit in our area, and this is an excellent way to get them together for seminars near their neighborhoods. However, I was unable to find a way of correcting an address without creating a new URL for it. Is there any way to go back to an existing URL and revise an address?
    I just saw above that the mapping is not necessarily meant for large numbers of addresses–we have 200 or so–is this true?
    Thank you for your attention and help.

  5. Posted February 23, 2010 at 10:13 pm | Permalink

    Hi Ana

    Yes, you are right about not being able to edit saved maps. This was a decision I made early on, since I didn’t want to force users to sign up for the service, and create a password (which they might forget, and then I would need to create a way for them to recover the password, etc). So, once you create a map, it is final. You are certainly welcome to create a new map, but your old one will remain. If you have frequently changing data, I suggest creating a naming scheme, like ‘AnasNonProfitFeb2010’. Next month, you can create the new version, ‘AnasNonProfitMarch2010’.

    Also, as for the large maps question, there should be no problem with that. The updates described in this post actually were designed in part to better support large maps, and help ensure that they will load as quickly as possible after they are created. You might notice a delay when the map is created, but after that, it should be pretty quick.

    Of course, if you are experiencing problems with large maps, please let me know using the contact link at the top of this page. It would be helpful if you could include the full list of addresses so that I can try to figure out the cause of the problem.


  6. Kim
    Posted April 16, 2010 at 4:40 pm | Permalink

    Is there a way to have the points on the map labeled with the address?

  7. Greg
    Posted July 28, 2012 at 5:36 pm | Permalink


    I love your website for plotting multiple locations on Google Maps over the last several years. Thanks for making it public. I’ve used it for a variety of purposes, most recently for plotting the addresses of soccer team players to help their parents create carpools for travel games.

    Here’s a suggestion for your consideration. The area displayed in a plotted map is quite short on the north-south axis yet wonderfully wide east-west. The result is that maps with even a modicum of north-south distance between points have to be zoomed out and thus show less detail than desired. If you could make the plotted maps use more of the north-south real estate on a screen, thus showing greater north-south geography, a user could generate maps with much more detail.

    Thanks again.

  8. Posted July 30, 2012 at 8:37 pm | Permalink

    Hi Greg

    I’m glad you find it useful! Your suggestion about the shape of the map is a good one. Others have suggested it as well. I am working on a major overhaul of the site to help with some scalability issues, and I will see if I can improve the vertical area of the map as well.


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