Portainer allows you to export any Docker image that is stored in any node. This is useful when you need to move a container from a one host to another or simply make backup of the images.
Note: Be advised that when you export a container to a tar file, the volumes are not exported with it. You need to save the data from those volumes in a another way.
To export images, click Images, select the image you want to export and click Export.
You will see a pop up warning you about that the export may take several minutes, this time depends of the size of your image. Click Continue.
When the process is ready you will see a pop up at the top right corner and you will see that your image is downloading: