Display GPX file on hi-res topo map (USA) and OSM map (world)

Gmap4 (google it) is an enhanced Google map viewer that is free for non-commercial use. You can use it to display your GPX files on the highest resolution seamless topographic map that is available anywhere online. These hi-res topos cover the USA (except maybe Alaska).

When you open a Gmap4 link with a mobile browser on a smartphone or tablet, then it automatically displays a touch-friendly interface. A mouse interface is automatically displayed on desktops/laptops.

To display your own GPX file with Gmap4:
1. Put your GPX (or KML, KMZ, TPO) file online.
2. Edit the q parameter in the above link so it points at your file instead of pointing at my file. See the examples on the homepage.
3. Paste the revised link into your browser.

Google Sites provides free file hosting and you can find step-by-step instructions by searching the Gmap4 Help file on "google sites". The Gmap4 homepage has a link to the Help file.

Tip: Do not use any spaces in your file name. Use the underline character instead.

If you are in Canada, you can display your GPX files on vector topos.

If you are not in the USA or Canada, then a good basemap to use is the OSM Cycle map which includes topographic lines and crowd-sourced trails.

When you are making a link to display a GPX file (or other supported file type), then the only *required* parameter is ‘q’ which is the complete link that points to your file. If you make a Gmap4 link that does not include the ‘q’ parameter, then the default basemap (t=t1, Google terrain) will be displayed.
......gmap4.php?q=__________

To specify a basemap to display when the map opens, include the ‘t’ parameter:
......gmap4.php?t=____&q=__________
To see the allowable values for the ‘t’ parameter, please search the Gmap4 Help file on ‘t8’ and then scroll up just a bit to see the full list.

NOTE! If you are using Gmap4 to display GPX (or TPO) files, then it is very important that you read about the ‘refresh’ parameter in the Help file.

Here are a few things you can do after the map opens:
* Double click. Center the map at the spot clicked.
* Right click. Display coordinates in various forms and get draggable directions.
* Menu ==> Link to this map. Get a link that will reproduce the map you see on your screen.
* Menu ==> My location. Uses the GPS in your mobile device to center the map at your location.
* Menu ==> Search. Includes searching on UTM coordinates.
* Menu ==> Draw and save. Trip planning with GPX output. One click can make both a waypoint and routepoint.
* Menu ==> Hill shading. Variable hill shading for the “t4 Topo High” basemap.
* Menu ==> UTM - LatLng - Off. Display UTM grid.
* Menu ==> Declination. Get the current magnetic declination for the center of the map.

Some forums allow Gmap4 maps to be embedded as ‘live’ maps in the body of forum posts.

And if you are savvy about GIS, then you can display your GPX file on top of any data that is available from GIS servers via either the REST interface or WMS interface. To see examples of Gmap4 displaying GIS data, go to the homepage ==> GIS viewer ==> Part 4.

If you do a google search on Gmap4, the first ‘hit’ is the homepage where you will find a FAQ, examples, quick start info (in the Help file) and more to quickly get you up to speed.

Joseph, the Gmap4 guy
Redmond, WA