Any 911 dispatcher or SAR team can ask a wireless caller to browse to "", open that web page and soon read off their coordinates usually with a 10 meter or better location accuracy.

FindMeSAR is a backup option that a 911 dispatcher can consider using when other methods of locating a wireless caller fail.

There are various ways that a 911 dispatcher can get the location for a wireless caller. The caller might provide a street address or the caller might describe landmarks they can see. Also in the USA any wireless carrier that handles a call to 911 is required to make "Phase 2" coordinates for the caller and an accuracy value available to the 911 dispatcher within 30 seconds. But note that there are large exemptions to that requirement.

Some wireless callers to 911 cannot describe their location for various reasons. What if the carrier handling that call has exempted the call from the "Phase 2" location requirements? Or what if the carrier provides "Phase 2" coordinates but the accuracy value is 3,000 meters and the caller is on foot in the forest? Or what if the "Phase 2" coordinates are never available for some unexplained reason? Another source of problems are coordinates provided by the caller that turn out to be wrong by a mile or more.


Most people that use a cell phone to call 911 are holding a GPS in their hand (inside their phone). The data produced by that GPS will usually be the fastest way to get coordinates for the caller with excellent location accuracy. It makes no sense to ignore that high quality GPS data when it can so easily and quickly be obtained with the FindMeSAR browser app.

The 911 dispatcher can ask the wireless caller to browse to "". The caller simply opens that web page which right away starts using the GPS chip in the caller's cell phone to display their coordinates. Within one minute the caller's screen will display either (1) their GPS coordinates with an location accuracy under 10 meters or (2) a message with suggestions for getting better accuracy.

FindMeSAR uses five different colored screens. Each color corresponds to a different coordinate format as follows:

Blue = U.S. National Grid (USNG). Same as MGRS.
Green = UTM
Yellow = Decimal degrees
Red = Degrees and decimal minutes
Violet = Ordnance Survey Grid Reference

Search teams and other first responders in different jurisdictions use different coordinate systems. The 911 call-taker can instruct the caller to tap the "Next Format" button until the colored screen is displayed that corresponds to the coordinate format used in that jurisdiction.

This simple color coded system will go a long way toward eliminating mistakes caused by confusion over different coordinate formats.

Each time a cell phone determines its location it generates three pieces of data. FindMeSAR displays all three and they all should be provided to the 911 call taker.
1. Coordinates
2. Accuracy
3. Timestamp

If a circle is drawn at the coordinates and using the accuracy value as the radius then there is supposed to be a 95% likelihood that the caller is inside that circle.

The timestamp shows everyone that the coordinates are current and are not cached coordinates from earlier in the day when the caller was at a different location.

Also when you tap 'Stop' then after a short pause your elevation is displayed. This data comes from a federal server and only works (1) if you are in the USA and (2) online.

To get the best GPS data, the user should be outside with a reasonable view of the sky or at least next to a window. Also, FindMeSAR is intended for cell phones and tablets. If you open FindMeSAR with a desktop or laptop browser then the results are unpredictable.

First, the FindMeSAR browser app does not display cached (i.e. old) coordinates. It only displays fresh coordinates. By reading the coordinate and accuracy value displayed on the screen there is no possibility that the caller will give 911 any kind of 'saved' coordinate or just a coordinate without also providing the equally important accuracy value.

Note! You should never use an app that displays coordinates but does not display the related accuracy value. After all, if the undisclosed accuracy value is 3,000 meters, then what good are the coordinates?

Second, FindMeSAR does *not* get just a single coordinate for the user. Instead, it gets a continuous stream of coordinate data. Usually the accuracy value will start out quite high but within 30 seconds will be under 10 meters.

During that process, FindMeSAR monitors the GPS datastream and displays appropriate messages if coordinates with good accuracy are not displayed in a reasonable time. For example, one message that might appear prompts Android users to change a setting on their phone in order to obtain much more accurate coordinates.

Sometimes a person who is lost can rescue themselves if they simply have a good map that shows their current location.

FindMeSAR includes a "Display map" button that will show the user's current location on a USA map. The map is displayed by GISsurfer which is a general purpose web map that is also produced by Mappingsupport. When the map opens a small red circle will follow the user and continue to show their position as the user travels. After the map opens the user can change the basemap if that would be useful.

In the USA and Canada the user can display a detailed topographic map by tapping the basemap button (next to the Menu button) and selecting "ESRI scanned topo USA" or "Canada Toporama".

Note! The GISsurfer map will only open if the cell phone is online.

For more information about the map please see the GISsurfer homepage.

Go outside and start FindMeSAR on your cell phone. After the accuracy drops to 10 meters or lower then you can check the location accuracy of the coordinates that are displayed by tapping the "Display map" button. After the map opens, tap the basemap button (next to the "Menu" button). Select the aerial "Esri aerial clarity". Check to see if the geolocation symbol does a reasonably good job of showing your location on the aerial.

The first time you open FindMeSAR a copy of this web app is automatically saved in a special part of your phone's memory called the application cache. This is *not* the same thing as the cache that your browser routinely uses. You can then open FindMeSAR when your phone or tablet is offline and it will work fine.

FindMeSAR also remembers which coordinate format you were looking at when you previously stopped using it. That same coordinate format will be displayed right away the next time you open this browser app.

You can add the FindMeSAR icon to your home screen and/or add a bookmark in your browser. Then to open this webpage when you are online or offline, simply tap the icon or bookmark.

If you open FindMeSAR when you are online then any updates are automatically saved on your phone.

iOS Safari users: To delete FindMeSAR from the Safari application cache do Settings ==> Safari ==> Advanced ==> Website data ==> Edit. Select Delete.

Chrome for Android users: Below are some general instructions. If this does not work for you then try a google search: Chrome for Android clear application cache (your phone model).
Settings ==> Apps (or Applications) ==> FindMeSAR ==> Clear cache and app data.

The FindMeSAR browser app can be used anywhere. If you know someone in a different country, invite them to give it a try. Remember, for the most accurate GPS coordinates the user needs to be outside with a reasonable view of the sky.

FindMeSAR is open source written in a simple coding style using javascript. Any software developer can look at the code and confirm that nothing strange is going on.

Here is documentation for the
browser geolocation API.

FindMePro is a research app that is intended to help the user discover how different settings on their cell phone affect the location accuracy of the coordinates that their phone produces. This is another public service project from MappingSuppport.

The following link starts FindMePro. For more information please see the "About" button.
Open FindMePro

In early 2016 Joseph learned that all too often 911 call centers do not have accurate location coordinates for a caller that is using a cell phone. He then developed FindMeSAR as a public service anyone can use to provide a nearly foolproof way to give coordinates to 911 that have high location accuracy. This should help achieve the goal of less search and more rescue.

Joseph is also the developer of GISsurfer, PropertyLineMaps and various other projects related to online mapping. For information about these other projects and contact information please visit

Donations are gratefully accepted.

By using the FindMeSAR software you agree that you are doing so entirely at your own risk. You further agree that you will not make any kind of claim or file any lawsuit against the developer of this software.

The FindMeSAR software does not retain your location data and does not share your location data with anyone.

Reminder: In the USA any wireless carrier that handles a call to 911 is required to make reasonably good coordinates for the caller available to the 911 dispatcher within 30 seconds. Often times this technology works fine. And often times a wireless caller to 911 can provide a street address or otherwise sufficiently describe their location. FindMeSAR is intended to be a backup option for when other location methods fail.

Voice and data at the same time

This part discusses whether a cell phone caller can talk to 911 and run FindMeSAR at the same time. In other words, can the caller do voice and data at the same time? There are several possibilities depending on the circumstances.

1. If a caller previously opened FindMeSAR on their phone then this browser app is already installed on their phone. The caller should be able to talk to 911 (or anyone else) and run the app at the same time. Since this browser app is already installed on the phone no internet data is required. The phone is simply making a voice call and running a browser app already installed on the phone. The issue of voice and data at the same time is not present.

2. The 911 dispatcher could ask the caller if there is a second cell phone available. If so, the second cell phone could browse to while the first cell phone continues the call with the 911 dispatcher.

3. 4G phones with VoLTE (Voice over LTE) technology typically can do voice and data at the same time. However, this might depend on the carrier than handles the wireless 911 call. Remember, all carriers are required to handle all 911 calls. Thus a Verizon phone that calls 911 might have that call handled by a tower for carrier xyz. Does that xyz tower have to have VoLTE technology in order for the caller to do voice and data at the same time? If anyone knows the answer (no guessing please) I would appreciate hearing from you.
Contact Joseph

4. If a caller (a) does not already have FindMeSAR on their cell phone, and (b) a second cell phone is not available and (c) the cell phone cannot do voice and data at the same time, then the 911 dispatcher will need to tell the caller to hang up, browse to, tap the “Next format” button to go to a certain colored screen, wait briefly for the accuracy value to get down to 10 meters or so and then call 911 back. Yes, dispatchers never want to stop a call. But doing so might be the only way to quickly get good quality coordinates for someone who needs help.

There is another issue related to situation #4. When a 911 call ends for any reason, then the caller’s phone is apparently ‘locked up’ for 5 minutes. Apparently the idea is to make it easy for the 911 dispatcher to call back. The user might be able to pull down a ‘notification’ screen and then cancel this 5 minute timer. Otherwise the user will have to wait 5 minutes before browsing to

FindMeSAR Known Issues

If you find a program bug or have a suggestion for an improvement please send an email. You will find contact information near the bottom of "Read part 3".

For bug reports please include:
1. Screenshots that show the problem
2. The browser(s) you tried
3. Make and model of device you are using
4. Operating system version

Starting FindMeSAR
Save the FindMeSAR icon on your home screen. Tap that icon and this web app will open. If there is a new version and you are online, then the new version will be installed on your phone. You can also type into a browser bar and automatically get any new version.

Caution: If you have an iPhone and start FindMeSAR via a shortcut icon on your homescreen then you do *not* automatically get any new version. (I have reported this to Apple as an iOS bug.) If this is how you start the app then after it starts you should reload it. This 2-step method will ensure you get any new version.

If FindMeSAR opens but never seems to work right then here are some things you can try.
1. Your location services need to be 'on'.
2. iOS users need to give permission to their browser to use location services. Scroll down on the screen where you turn location services on/off. Your browser permission needs to be set to "While using".
3. iOS users should also make sure they are using the latest version of iOS.
4. Look at the "FindMeSAR Update Log" lower on this page and note the most recent version number. Check to see if that version number appears on your screen when you start FindMeSAR.
5. If you saved a shortcut icon on your homescreen, then delete it.
6. If you saved a bookmark, delete it.
7. Do a soft reset of your phone.
    iOS users: Press and hold both the Home key and Power key. When the Apple logo appears (about 10 seconds) then release both keys. Wait for the phone to restart.
    Android users: (Your phone might require a different method.) Press and hold the Power button. Tap Restart. Tap Restart again to confirm.
8. Open the app
9. A fresh copy of the app should now be installed on your phone. Try it and see if it works OK.
10. If you are still having trouble then delete the app from your phone and then reinstall it by browsing to If you need help deleting the app see "FindMeSAR Part 3" higher on this page.

GPS antenna
Take care not to block the GPS antenna with your hand. Hold your phone in portrait orientation with your hand at the lower part of the phone. There have been some reports of a phone's case interfering with the GPS signal.

Voice and data at the same time.
Please tap the button “Read FindMeSAR part 4”.

iOS users
For online use, most browsers should be fine. For offline use, please use the Safari browser.

FindMeSAR Update Log

When you open the app the version number appears on the "about" button.

Version 2.5 FindMeSAR 6-7-2021
Added support for Ordnance Survey (OS) Grid Reference. The background color for this screen is light violet. This system is used in the United Kingdom. Also deleted apcache coding which is now deprecated.

Version 2.4 FindMeSAR 11-17-2020
When the accuracy value gets to 100 feet or less (~30.5 meters), then a "Copy to clipboard" button will appear. That button will copy both the coordinates and accuracy value.

Version 2.3 FindMeSAR
Added support for service worker technology. This is one of the methods that GISsurfer uses to work offline. The older technology for offline use known as AppCache is still supported by GISsurfer as a fallback.

Version 2.2 FindMeSAR
1. When your coordinates appear on the screen and you tap "Stop", then after a brief pause your elevation will be displayed. This only works for locations in the USA and your browser must be online in order to retrieve the elevation data from a federal server.
2. Display of UTM coordinates has changed. After the UTM zone number a letter appears which is the latitude band. This format is how the USGS now displays UTM coordinates.

Version 2.1 FindMeSAR 5-18-2016
After the recent server update some people reported that FindMeSAR was not working correctly. Information has been added under the "Known issues" button (scroll up on this page) showing the recommended steps to delete the app and then load a fresh copy.

Version 2.0 FindMeSAR 5-10-2016
The app now uses HTTPS and you will see a padlock in the browser bar. Please update your link to
HTTP links will continue to work and the app will automatically open using HTTPS.

Version 1.5 FindMeSAR 4-24-2016
The app now remembers the last coordinate format that was displayed. The next time you open the app that same coordinate format will be displayed.

Version 1.4 FindMeSAR 4-23-2016
Minor tweaks so the "Display map" button will appear on smaller phone screens without having to scroll.

Version 1.3 FindMeSAR 4-15-2016
Fixed a bug in the UTM coordinate display

Version 1.2 FindMeSAR 4-14-2016
The app has been moved from the domain to a domain just for this app. Here is the new link:

Version 1.1 FindMeSAR 4-11-2016
This browser can now be used offline. For more information, please read "Part 3" (see button above).

Version 1.0 FindMeSAR 4-8-2016 application launched.