Config transforms

    Sometimes you just need your configuration files to be a little bit different after you deploy. It's possible to transform your config files for each environment in your project.


    To transform any file that ends with .config, you can add a file with the extension .{environment}.xdt.config in the same folder.
    The {environment} part needs to be replaced with the target environment, for which there's currently 2 possibilities for each project:

    1. development
    2. live

    Note: Some sites have a 3rd option: staging.


    If you wanted to do a transform on your web.config file in the root of your site, you can create two files in the root of your site:

    1. web.development.xdt.config

    Then, whenever you deploy from local to development, the transforms in web.development.xdt.config will be applied. And of course when you deploy from development to live, the transform will be applied.

    Note: if you only want to transform the file on the live environment then you don't create the development.xdt.config.

    Test your config transforms

    Before applying the config transform files to your environments we recommend that you run a test using this tool: Webconfig Transformation Tester

    Using the tool will let you test whether the config transform file transforms your config files correctly. The tool can be used for all config files.

    All config files

    For each deploy, we'll search for all of the .{environment}.xdt.config files in your site and apply transforms, so you can also transform (for example) ~/config/Dashboard.config by creating a ~/config/ file. Just make sure the transform file follows the naming convention and it exists in the same folder as the config file you want to transform.

    Baseline config transforms

    It is possible to apply config transforms for specific child sites from a baseline. For more info see Baseline Configuration Files documentation

    Including transforms in Umbraco packages

    For package developers it can be useful to add a config transform that needs to happen on each environment, for example if you're making a package called uPaintItBlack where you want to set an AppSetting in web.config. The AppSetting in development should be a red door so you set the AppSetting value to "red". On staging it should be a green sea so you set the AppSetting to "green" (or to a deeper "blue"). Of course on live you've painted it black so you set it to "black".

    In that case you can make 3 transform files, the filename needs to start with something that's specific to your plugin, it can be any word, for example RollingStones or uPaintItBlack:

    • ~/uPaintItBlack.web.development.xdt.config
    • ~/uPaintItBlack.web.staging.xdt.config
    • ~/

    Again, these type of prefixed files can be placed next to any other file so if you also need to transform ~/config/Dashboard.config specifically for your plugin then you can create ~/config/uPaintItBlack.Dashboard.{environment}.xdt.config

    Forced transforms

    Whenever you deploy changes to any of your environments we force some config transforms to help make sure optimal settings are set for your website.

    Web.config forced transforms

    These are the transforms we do on the root web.config file regardless of the custom transforms you might have specified above, we enforce these transforms always.

    On live environments only:

    • We set debug="false" on the compilation node in system.web
    • We set mode="RemoteOnly" on the customErrors node in system.web

    On all other environments:

    • We set debug="true" on the compilation node in system.web
    • We set mode="Off" on the customErrors node in system.web
    • We set waitChangeNotification="3" maxWaitChangeNotification="10" on the httpRuntime node in system.web
    • We set numRecompilesBeforeAppRestart="50" on the compilation node in system.web
    • We set the smtp host="" if the host was set to

    Note that for the compilation debug and the customErrors mode there is a toggle in the Umbraco Cloud portal to temporarily toggle the opposite setting. This will change the debug/customErrors mode until the next deploy to this environment on each deploy the forced transforms will be performed again.

    Toggle debug mode