ImageLayers is a great tool, when you are looking at shipping your containers or images around. It will take into account everything that is going on in every single layer of a particular Docker image and give you an output of how much weight it has in terms of actual size or the amount of disk space it will take up.

This screenshot is what you will be presented with while navigating to the ImageLayers website: https://imagelayers.io.

You can search for images that are on Docker Hub to have ImageLayers provide information on the image back to you. Or, you can load up a sample image set if you are looking at providing some sample sets or seeing some more complex setups.

In this example, we are going to search for the wordpress image and select the latest tag. Now, you can search for any image and it will do auto-complete. Then, you can select the appropriate tag you wish to use. This could be useful if you have, say, a staging tag and are thinking of pushing a new image to your latest tag, but you want to see what impact it has on the size of the image.

So, let's walk through an example. In this example, we are going to select a mysql image and the latest tag. We will use this since it is a common image that most people will use at some point in their Docker experience.

Once we click on Save Changes from the previous item, we will be shown something similar to the preceding screenshot (now, this will vary depending upon the image you have selected in your search). This displays some information at the top, such as the total image size, unique layers, the average layer size, and the largest layer size. This will help you hone in on a particular layer that might have grown wildly.

The layers are broken down on the left-hand side of the previous screenshot. We can see what action is being done at each level as the size that it adds to the overall image per layer.

Upon hovering on a particular layer, you will be given information on it at the bottom of the screen in a black box. This will show how each action is layered one after the other so as to help see the command structure of the image.

The preceding screenshot is an example of what you might see if you were to click on the sample image set from the main screen. As you can see, this one is quite complex; not only does it have a lot of layers, but it also has a lot of images that are being used. This could be something you would see while adding multiple images to see your desired output.