Gaining more WMS speed through enabling the QGIS cache directory

Interestingly the WMS caching is not enabled by default in QGIS. To better enjoy WMS/WMS-C/WMTS connections – if you have some disk space to dedicate – it is a good idea to enable the cache in these few steps:

Go to the menu entry Settings >> Options:

Enabling the QGIS WMS cache - step 1

Enabling the QGIS WMS cache – step 1

Go to tab “Network“. Therein, in “Cache settings“, select the “Directory” and choose a folder for the cache files. Be sure that there is free space for lots of megabytes can be stored there over time. And this directory should ideally be located on a fast disk (if you have several).

Here I choose the existing “tmp/” folder in my HOME directory and create inside a new folder “qgis_wms_cache”:

Enabling the QGIS WMS cache - step 2

Enabling the QGIS WMS cache – step 2: create new “qgis_wms_cache” cache folder

Eventually we change the “Default expiration period for WMS-C/WMTS tiles (hours)” to more than 24 hours (as it would be rather useless…). Here I change to 24*30 = 720 hours. And the cache size we increase as well, here to 250MB (written as 250000 since it is to be given in kilobytes):

Enabling the QGIS WMS cache - step 3

Enabling the QGIS WMS cache – step 3: increase expiration period for tiles and cache size

Now we press “OK” and close the dialog. Time to try out a WMS service, zoom back and forth… and:

This entry was posted in Blog, QGIS on by .

About neteler

Markus Neteler , a founding-member of the (D-A-CH), (Italy), and the Open Source Geospatial Foundation (OSGeo), is head of the GIS and Remote Sensing Unit at the Research and Innovation Centre of the Fondazione Edmund Mach, Trento, Italy. He is author of several books and chapters on GRASS and various papers on GIS applications. Being passionate about Open Source GIS, he became a GRASS GIS user in 1993 and a developer in 1997, coordinating its development since then.

3 thoughts on “Gaining more WMS speed through enabling the QGIS cache directory

  1. Thomas

    I don’t think that ‘pure’ WMS-Layers are cached. I tested it with fiddler and recognised that only WMS-C / WMTS are cached but not normal WMS-layers. So your sentence “To better enjoy WMS/WMS-C/WMTS connections…” is a bit misleading. Only the capabilities-document is cached for normal WMS-layers.

    1. neteler Post author

      Thanks for your comment. I didn’t check the source code but got a notable speed-up. Maybe a QGIS developer could shed some light on this…

  2. Pingback: Habilitando cache no QGIS para camadas WMS – Blog do Fernando Quadro

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