Docker Desktop using too much disk space on a Mac

By EgeTech LTD · October 6, 2026 · 2 min read

On a Mac, Docker does not store images and containers in many small folders. Docker Desktop runs a small virtual machine, and everything lives in one large disk file inside it. That file can reach tens of gigabytes and is easy to forget, because no single folder shows what is in it.

See what takes the space

Ask Docker, not the Finder:

docker system df

You get a table with Images, Containers, Local Volumes and Build Cache, with the total size of each and how much is reclaimable. Add -v for the detail of each image and volume.

Remove what is safe to remove

The gentle option. Removes stopped containers, unused networks, dangling images and the build cache:

docker system prune

Docker lists what it is about to delete and asks you to confirm.

Remove only the build cache, which is often the biggest part:

docker builder prune

Remove images you are not using:

docker image prune -a

-a removes every image that is not used by a container, not only the untagged ones. You will pull them again when you need them.

The dangerous one

docker system prune -a --volumes

This also removes volumes that no container uses. Volumes are where databases keep their data. A volume that is not attached to a running container right now is not necessarily unneeded. Run docker volume ls and look before you add --volumes.

Why the disk file stays big

Docker Desktop keeps its data in a virtual disk image, a file under:

~/Library/Containers/com.docker.docker

The exact file name depends on your Docker Desktop version. When you prune, Docker frees space inside that file. Whether macOS gets the space back immediately depends on the version and the settings, and it often does not. If the file stays big after a prune, look in Docker Desktop’s settings: the Resources section shows the disk image size and limit, and recent versions offer a way to reclaim space or reset the disk image. Resetting deletes everything, so use it only when you are happy to lose all images, containers and volumes.

Set a limit so it does not grow forever

In Docker Desktop → Settings → Resources, you can limit the size of the virtual disk. A smaller limit makes the problem visible sooner: Docker will complain before your Mac fills up.

What it costs

• Images and build cache: pulled or built again next time, so a slower start.
• Containers: stopped ones are removed. Data that was only inside them is gone.
• Volumes: data that was only in them is gone for good.

One more reason your disk looks full

Docker is one of several things that count toward the grey bar in Storage. See why System Data gets so big on a developer Mac and the full checklist.