DMT Wallpaper Changer

Wallpaper Changer will routinely change your Windows wallpaper using a variety of sources for images.

'General' options

Wallpaper Changer general

The first few items allow you to specify when and how often you want the wallpaper changed.

'Multi Monitor' allows you to specify how multiple monitors should be treated. The available options are:

  • One image stretched over all monitors.
  • Same image on each monitor.
  • Different image on each monitor (all changed together).
  • Different image on each monitor (only one changed at a time). Initially this will update the image on all of the monitors, but after that whenever it is time to update the wallpaper, it will just update one monitor at a time in turn.

If the image size is not the same size as the rectangle enclosing all of the selected screens, then the 'Fit' combo box determines any scaling that need to be applied to the image. The available options are:

  • Over stretch to cover the monitor(s). This is normally the best option.
  • Under stretch so as not to clip image. This will result in bars being added.
  • Center image without any stretching. If your image is larger than the selected monitors, then the image will be clipped. If The image is smaller than the selected monitors, then a border will be displayed around the image.
  • Stretch image to fill monitor(s) - ignores aspect ratio. This will stretch or shrink so that the whole image is displayed occupying the whole area of the selected monitors.

Initially no providers (of images) are set up, so click on the 'Providers' options to add/edit/delete providers.

'Properties' options

Wallpaper Changer properties

Once DMT has generated a wallpaper, this will show the source and any available details of the image(s) used.

'Providers' options

Wallpaper Changer providers

The weight will indicate the frequency that provider should be used, with the higher the value, the more often it is used. So if you have one provider with a weight of 1 and another with a weight of 4, then you are 4 times as likely for an image to be chosen from the provider with a weight of 4 than from the provider with a weight of 1.

Three provides are currently supported:

  • Local disk - provides images saved in a folder (with an option to look in sub-folders) on an attached drive. You can also specify different directories for individual monitors and for any monitors in portrait orientation.
  • Flickr - provides images from You will need an API key from flickr for this. See below for more details.
  • Unspash - provides images from Please see their terms and conditions on the use of these images and in particular please note that the usage is restricted to persons who are at least 18 years old.
  • URL - provides images from the given URL. This works best for URLs that return a different random image each time they are requested.
  • Random shapes - generates images composed of random shapes.

If you use a provider that takes images from an external source, please respect any terms and conditions they may have.

Flickr API Key

To download images from Flickr, you will need to obtain an API Key from Flickr.

To obtain the API key, visit and click on the "Apply for your key online now" link. You will need a Flickr or Yahoo account to do this. Then click on the "APPLY FOR A NON-COMMERCIAL KEY" button. For the name of the app, enter "DMT" and for the details enter "For use with the Dual Monitor Tools open source application". When you have the key, you can select flickr as a provider from DMT's list of providers and paste the key into last field of the dialog:

Flickr provider form

Windows 10 File Explorer bug

If you find when you are using File Explorer that it scrolls to the top whenever the wallpaper is changed, this is due to a bug in Windows 10. It can be avoided by turning off "Automatically pick an accent colour from my background" in the "Colours" section of the personalise settings. (Right click on the Windows background to get at this.)