Interactive Polyline Encoder Utility

Polylines in Google Maps are formed as a set of latitude/longitude pairs. In addition, for each point in an encoded polyline, a level can be specified indicating that the point should appear on that level and any level higher (i.e. any decrease in zoom.). If a point does not appear on a given level, then the line will go from the last visible point to the next visible point. Note that the first and last points must be Level 3 points, otherwise the polyline won't display on all levels.

You can use this interactive utility to compute the encoding for a polyline.

1. Click on the map to place the first point of your polyline. You may drag the marker to adjust the location of the point.
2. If necessary, specify the appropriate level for the point in the "Min zoom level" field.
3. Click the "Add Point" button to add it to the Point List.
4. Repeat for each point of your polyline.
5. The polyline encoding will appear in the Encoded Polyline and Encoded Levels fields below. Use these values for points and levels when you create your GPolyline.