How to Use docker system df to Check Disk Usage

Use the docker system df command to see how much disk space Docker is using for images, containers, volumes, and build cache. It gives a summary of storage usage so you can manage space effectively.

Syntax

The basic syntax of the docker system df command is simple and has optional flags to customize output.

• docker system df: Shows disk usage summary.
• --verbose: Shows detailed information about each object.
• --format: Formats output using a Go template.

bash

docker system df [OPTIONS]

Options:
  --verbose    Show detailed information on space usage
  --format string   Format output using a Go template

Example

This example runs docker system df to display a summary of disk usage by Docker objects like images, containers, volumes, and build cache.

bash

docker system df

Output

TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              5                   2                   3.45GB              1.2GB (34%)
Containers          3                   1                   150MB               100MB (66%)
Local Volumes       4                   3                   500MB               200MB (40%)
Build Cache         0                   0                   0B                  0B

Common Pitfalls

Common mistakes when using docker system df include:

• Expecting it to clean space automatically — it only reports usage.
• Not using --verbose when detailed info is needed.
• Confusing SIZE with actual reclaimable space.

To free space, use docker system prune separately.

bash

docker system df --verbose

Output

Images space usage:
  REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE                SHARED SIZE         UNIQUE SIZE         CONTAINERS
  alpine              latest              7a8c8a1e7f3b        2 weeks ago         5.57MB              0B                  5.57MB              1
  ubuntu              20.04               1d622ef86b13        3 weeks ago         72.9MB              0B                  72.9MB              0
Containers space usage:
  CONTAINER ID        IMAGE               COMMAND             LOCAL VOLUMES       SIZE                CREATED             STATUS              NAMES
  3c1a2b3c4d5e        alpine              "/bin/sh"           0                   2MB                 2 days ago          Up 2 days           friendly_morse
Local Volumes space usage:
  VOLUME NAME         LINKS               SIZE
  my_volume           1                   200MB

Quick Reference

Option	Description
docker system df	Show disk usage summary
docker system df --verbose	Show detailed usage per object
docker system df --format	Format output with Go template
docker system prune	Remove unused data to free space

Key Takeaways

Use docker system df to check Docker disk usage for images, containers, volumes, and build cache.

Add --verbose to see detailed information about each Docker object.

The command only reports usage; use docker system prune to clean up space.

Understand the difference between total size and reclaimable space shown in the output.

Use --format to customize output for scripts or automation.