KML and KMZ Benchmarking

When displaying data over Google Maps using KML and KMZ files there is always the doubt of whether it is better to use one type of file or the other. KML is the standard XML type file used by Google to display data over their maps, while KMZ is a compressed KML file. Compressing a KML file dramatically reduces its size, for example in the example used to a 26.22% of the original size, helping to save the typically scarce server space. Even though, less space does not always mean faster loading times, because it is necessary to uncompress the files, which may take a long time.

In order to find out which kind of file has a better performance and is best to work with, a benchmark test was performed. Results stated that between the moment a link was clicked in Google Maps and it fully opened in Google Earth the time elapsed was a 58.19% faster when using KMZ. The technical details of the benchmark test and the shape used to do the test can be seen under these lines.

File	KML	KMZ
Number of polygons	2103
Size in KB	5.705	1.496
Relative size (%)	100	26.22
Loading time (sec)	28.94	12.1
Relative time (%)	100	41.81
Software used	Google Earth
Version	4.2.0205.5730
OS	Windows XP SP2
Processor	Intel Pentium M 1.73 MHz
RAM	1GB
Web Browser	Internet Explorer
Connection speed	2MB/sec Cable
Files hosted at	www.gisngeo.com

This is the file used to do the benchmarking: