How to remove old and unused Docker images

Question

When running Docker for a long time, there are a lot of images in system. How can I remove all unused Docker images at once safety to free up the storage?

In additio

Answer 1

Update the second (2017-07-08):

Refer (again) to VonC, using the even more recent system prune. The impatient can skip the prompt with the -f, --force option:

docker system prune -f

The impatient and reckless can additionally remove "unused images not just the dangling ones" with the -a, --all option:

docker system prune -af

https://docs.docker.com/engine/reference/commandline/system_prune/

Update:

Refer to VonC's answer which uses the recently added prune commands. Here is the corresponding shell alias convenience:

alias docker-clean=' \
  docker container prune -f ; \
  docker image prune -f ; \
  docker network prune -f ; \
  docker volume prune -f '

Old answer:

Delete stopped (exited) containers:

$ docker ps --no-trunc -aqf "status=exited" | xargs docker rm

Delete unused (dangling) images:

$ docker images --no-trunc -aqf "dangling=true" | xargs docker rmi

If you have exercised extreme caution with regard to irrevocable data loss, then you can delete unused (dangling) volumes (v1.9 and up):

$ docker volume ls -qf "dangling=true" | xargs docker volume rm

Here they are in a convenient shell alias:

alias docker-clean=' \
  docker ps --no-trunc -aqf "status=exited" | xargs docker rm ; \
  docker images --no-trunc -aqf "dangling=true" | xargs docker rmi ; \
  docker volume ls -qf "dangling=true" | xargs docker volume rm'

References:

• docker ps -f
• docker rm
• docker images -f
• docker rmi
• Docker v1.9.0 release notes
• docker volume ls
• docker volume rm