How to Find Docker Image Size Quickly and Easily

Use the docker images command to list all Docker images with their sizes. For detailed size info of a specific image, use docker image inspect <image_name> and check the Size field.

Syntax

The main commands to find Docker image sizes are:

• docker images: Lists all images with their sizes.
• docker image inspect <image_name>: Shows detailed info including size in bytes.

Replace <image_name> with the actual image name or ID.

bash

docker images

docker image inspect <image_name>

Example

This example shows how to list all images with sizes and inspect a specific image's size in detail.

bash

docker images

docker image inspect nginx

Output

REPOSITORY   TAG       IMAGE ID       CREATED        SIZE
nginx        latest    4bb46517cac3   2 weeks ago    133MB

[
  {
    "Id": "sha256:4bb46517cac3...",
    "RepoTags": ["nginx:latest"],
    "Size": 139921856,
    ...
  }
]

Common Pitfalls

Common mistakes when checking Docker image sizes include:

• Using docker ps which shows running containers, not image sizes.
• Confusing image size with container size; containers can be larger due to added data.
• Not specifying the correct image name or tag in docker image inspect.

bash

Wrong:
docker ps

Right:
docker images

docker image inspect nginx

Quick Reference

Command	Description
docker images	List all images with size summary
docker image inspect	Show detailed info including exact size in bytes
docker ps	Lists running containers (not image sizes)

Key Takeaways

Use docker images to quickly see image sizes in a readable format.

For exact size in bytes, use docker image inspect <image_name> and check the Size field.

Do not confuse container size with image size; they are different.

Always specify the correct image name or ID when inspecting.

Avoid using docker ps to find image sizes as it shows containers only.