How To Clean Up Docker With Prune
Docker is a widely used containerization platform for building, running, and distributing applications. As you develop and deploy containers over time, Docker can accumulate unused objects like stopped containers, dangling images, unused volumes, and networks. These leftover resources consume disk space and may degrade system performance if not cleaned up.
This article explains how to use the docker prune command family to safely remove unused Docker resources. You’ll learn the differences between docker prune and manual deletion, how to use each prune variant effectively, and best practices to prevent accidental data loss during cleanup.
What Is docker prune?
The docker prune command family helps you remove unused Docker resources like stopped containers, dangling images, unused volumes, networks, and build cache, all in one go. It's faster and less manual than using docker rm or docker rmi.
Use docker rm when you need precision. Use docker prune when you want to clean everything efficiently.
The Short Answer Version
Common Options for docker prune
Most docker prune commands support the following options:
Use filters to avoid removing recently created resources during cleanup.
Clean All Docker Resources with docker system prune
Use this command to remove all unused containers, networks, dangling images, and build cache.
Command Syntax
Command Demonstration
Clean up all unused Docker resources interactively.
CONSOLEClean up all unused resources without confirmation.
CONSOLEClean up unused resources older than 48 hours.
CONSOLE
When to Use
- After heavy development or container churn
- When disk space is limited
- When no stopped containers or unused images are needed
Clean Docker Containers with docker container prune
Use this command to remove only stopped containers. Running containers are not affected.
Command Syntax
Command Demonstration
Remove all stopped containers.
CONSOLERemove all stopped containers without confirmation.
CONSOLERemove stopped containers older than 24 hours.
CONSOLE
When to Use
- After running short-lived containers during testing or development
- When stopped containers pile up over time
- To free up space without affecting running containers
Clean Docker Images with docker image prune
This command removes unused Docker images. By default, it only removes dangling images — images that are untagged and not referenced by any containers.
Command Syntax
Command Demonstration
Remove all dangling images.
CONSOLERemove all unused images (not just dangling ones).
CONSOLERemove unused images older than 72 hours.
CONSOLE
When to Use
- After building or pulling many temporary images
- When running out of disk space due to image layers
- To clean up old application builds not referenced by containers
Clean Docker Volumes with docker volume prune
This command removes volumes that are not referenced by any containers. Active or attached volumes are not affected.
Command Syntax
Command Demonstration
Remove all unused volumes interactively.
CONSOLERemove all unused volumes without confirmation.
CONSOLE
When to Use
- After deleting containers that previously used persistent volumes
- When temporary or test volumes accumulate over time
- To recover disk space tied to orphaned data
Warning
Volume data is not recoverable after deletion. Always verify which volumes are in use before pruning.
Clean Docker Networks with docker network prune
Use this command to remove Docker networks that are not connected to any running or stopped containers.
Command Syntax
Command Demonstration
Remove all unused networks interactively.
CONSOLERemove all unused networks without confirmation.
CONSOLE
When to Use
- After removing containers created with
docker-compose - When testing multi-container applications
- To clean up orphaned or auto-generated bridge networks
Clean Docker Build Cache with docker builder prune
This command removes the build cache created during image builds. By default, it only removes dangling (unused) cache layers.
Command Syntax
Command Demonstration
Remove dangling build cache interactively.
CONSOLERemove all unused build cache without confirmation.
CONSOLE
When to Use
- After frequent image builds during development
- When low on disk space
- To clean up intermediate cache layers that are no longer referenced
Troubleshooting Docker Prune Issues
Conclusion
In this article, you learned how to clean up unused Docker resources using the docker prune command family. You explored how to remove stopped containers, dangling images, unused volumes and networks, and build cache safely and efficiently. These commands help maintain a clean development environment and reduce disk usage.
Tags:Docker
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