How To Tag Docker Images

Docker image tags help identify versions of an image.

When you build or pull an image, the tag tells Docker which version you mean. If you do not mention a tag, Docker usually assumes latest.

Tags are simple, but they matter a lot in real projects.

Image name and tag

An image reference usually looks like this:

image-name:tag

For example:

nginx:latest
mysql:8
my-app:1.0

The part before : is the image name. The part after : is the tag.

Pull an image with a tag

You can pull a specific version:

docker pull nginx:latest
docker pull mysql:8

If you run:

docker pull nginx

Docker treats it like:

docker pull nginx:latest

Build an image with a tag

When building your own image, use -t:

docker build -t my-app:1.0 .

This creates an image named my-app with the tag 1.0.

You can check it with:

docker images

Tag an existing image

You can add another tag to an existing image:

docker tag my-app:1.0 my-app:latest

This does not duplicate the full image. It adds another name pointing to the same image data.

Tags for Docker Hub

To push an image to Docker Hub, the image name should include your Docker Hub username:

docker tag my-app:1.0 username/my-app:1.0
docker push username/my-app:1.0

Replace username with your Docker Hub username.

This naming tells Docker where the image belongs in the registry.

Why latest can be confusing

The latest tag does not always mean the newest or safest version. It is just a tag name.

Someone has to update it. In real projects, teams often use clear version tags:

my-app:1.0
my-app:1.1
my-app:2026-09-06
my-app:release-12

Specific tags make deployment easier to understand and rollback.

Good tagging habits

Use meaningful tags:

• Use 1.0, 1.1, or semantic versions for releases
• Use dev for development images
• Use latest only when you understand what it points to
• Include your registry username before pushing to Docker Hub

Written By: Shiva Srivastava