Max KML file size in Google Maps?

[Jailsea]

Hi

Apologies if this is a straight forward question but I have not been able to find a solution to this anywhere so far.

We are exploring the possibility of rapidly viewing simple information via Google Maps using KML exported from ArcGIS using Arc2Earth. Some minor style issues are found but these can easily be resolved by editing the kml file. However, large parts of the information appear to be randomly missing.

An error is shown in the left hand pane of Google Maps stating that parts of the file could not be displayed because it is too large. Does anyone know what the maximum size is?

The data in question can be viewed here

Thanks in advance for any help.

[weatherman22]

I get this error too, and only 65 of my placemarks display out of a possible 100 (or more).

I'm not sure if it is the file size which is limited or the number of placemarks within. The kml file itself is only 96.4kb. I have tried using a kmz instead but despite using GE to create it from the same placemark set as I was using for the kml file, Maps rejects the file entirely stating it is not a valid kmz or kml file.

Rather annoying as we can't use GE in work so was relying on Maps.

I wonder if the size limit can be circumvented by using the API.

Regards

Stuart

[Jailsea]

I have the same problem when using a kmz file. I'm surprised that at 96kb it isn't showing as I had assumed that the size limit was 100 kb.

I can't fined any reference to file size in the API..... but then again I'm definitely no expert so am probably missing it.

However, it does seem surprising that such a fundamental piece of information is so hard to find.

[tekgergedan]

Hi and welcome

I guess you are asking something with the Maps? I think there is a very few number of members having experience on that in this GE forum. There is no file limit in kml with GE (or nobody, as much I know, has reached that) (except a file-size limit which is mostly an image overlay size problem). Did you try your kml in GE? As long as you dont provide it to us, nobody can check it here.

[weatherman22]

He did provide it, in post 1!

[Jailsea]

Hia

Yep, the kml works fine in GE, but we really want to display the data in Google Maps so that it is accessible without requiring a client download.

I realise that this is a GE forum but I have posted the same question in the GM Google group but without a response

Thanks for taking a look, any help is greatly appreciated

[PenguinOpus]

Out of curiousity, why can't you use GE at work?

KML for Maps has some limitations right now, although things are improving over time. Very recently, KMZ and embedded icon/image support was added.

[weatherman22]

Can't use at work because

1. It would cost too much (the free version is for home use) and 2. Our IT section state that it conflicts with operational software (I don't know what).

[Culland]

I have the same problem and havent found any information anywhere on it. I have tried making it into a KMZ file which greatly reduced the file size, but the number of placemarks being returned is roughly the same, seems to vary between 65-71.

I tried removing parts of my placemarks, like description to see if I can get more points displayed, nothing I removed had a difference.

Cul

[dni]

There seems to be a method of using XSLT to transform the KML file into HTML that can then be read by Google Maps, posted here: http://cse-mjmcl.cse.bris.ac.uk/blog/2005/07/26/1122414882406.html

It doesn't work for me, but it could be a step in the right direction for what folks on this post are asking for...

[Jailsea]

Thanks for the pointer. This looks really promising and may provide the solution that I'm looking for, i.e. NOT using kml files!

Cheers

[mmclaren]

Hi Jailsea,

I've had a quick look at your KML and it contains around 260+ points and the same number of rectangular regions. The regions overlap and so currently this looks pretty nasty in both GE and Google Maps API pages.

520+ map objects on a Google Maps HTML page is also liable to be fairly slow. I've managed to cobble together something showing just the 260+ regions (based on GMap2 GOverlay example). I used XSL as a tool to extract the region data, I'm happy to share the XSL with you if you want it. The Google Maps API JavaScript can be added by hand after XSL does the hard work as a lot of GMaps JavaScript is pretty much boilerplate stuff.

http://cse-mjmcl.cse.bris.ac.uk/jailsea.html

I'm afraid I don't know anything about ArcGIS but I suspect you might be better off using a GIS aware database (such as PostGIS or GeoServer) to serve up a more filtered version of your data.

HTH

Mark

[Jailsea]

Hi Mark

Sorry I haven't replied earlier, this is the first opportunity I've had to revisit this material.

Thanks for what you have done, it looks impressive and may be very useful. I originally turned to kml as it offered the potential to produce a simple map very quickly from data that we already had. In fact it turns out not to offer that so I think that you are right in your suggestion to pursue a server delivered solution..... now if I just had the time.......

Thanks for all your help.
James

[simon_a]

Hello,

I tried a few KMZ files into Google maps and found that there appear to be two limits: a limit on the number of objects returned (as others have said, about 60) and a limit on the size of the uncompressed KML file (not KMZ, which it would seem doesn't matter).

This file of about 300KB, which uncompresses to about 946KB, will open in Google maps but only return about 60 objects:
File: http://bbs.keyhole.com/ubb/download.php?Number=96342
In Google Maps: http://maps.google.com/maps?f=q&hl=e...p;z=10&om=1

This KMZ file of about 57KB, which uncompresses to just over 1MB, returns an error:
File: http://bbs.keyhole.com/ubb/download.php?Number=257132
In Google Maps: http://maps.google.com/maps?f=q&hl=e...p;z=15&om=1

Other files I tried that uncompress to less than 1MB open in Google Maps, returning at least some objects, but those that uncompress to over 1MB do not.

Therefore, my guess is that there are two limits: a limit on the number of objects returned - about 60 - and a limit on the size of the KML code (uncompressed if from KMZ), which appears to be 1MB.



Simon.