Docker Buildx: Build Multi-Platform Images Like a Pro

When building Docker images, developers often face platform compatibility issues — especially when deploying to different architectures like amd64 or arm64 (used in newer Macs, Raspberry Pi, cloud servers, etc.). Thankfully, Docker Buildx is here to solve that problem.

In this post, you’ll learn what Buildx is, why it matters, and how to use it with real examples.

🔍 What Is Docker Buildx?

Docker Buildx is an extended build command that provides advanced features powered by BuildKit, including:

• Multi-platform image builds (e.g., linux/amd64, linux/arm64)
• Faster builds with cache
• Cross-platform CI/CD pipelines
• Export options for Docker Hub, tar files, and more

🤔 Why Use Docker Buildx?

Imagine building a Docker image on your Mac (which runs on ARM64) and trying to deploy it to a cloud server (which runs on AMD64). Without Buildx, this mismatch often breaks your app.

With Buildx, you can build a single image that works on multiple platforms like so:

docker buildx build --platform linux/amd64,linux/arm64 ...

No compatibility issues. No surprises.

🛠️ How to Use Docker Buildx

1. Set Up Buildx

Docker Buildx is built into Docker 19.03 and above.

Run this to create and use a new builder:

docker buildx create --use

(Optional) Bootstrap and inspect:

docker buildx inspect --bootstrap

2. Build a Multi-Platform Docker Image

Let’s say you have a simple Dockerfile:

# Dockerfile
FROM node:20-alpine
WORKDIR /app
COPY . .
RUN npm install
CMD ["npm", "start"]

Now build and push a multi-arch image:

docker buildx build \
  --platform linux/amd64,linux/arm64 \
  -t yourusername/yourimage:latest \
  --push .

3. Automate with GitHub Actions

You can integrate Buildx into CI/CD pipelines like this:

name: Docker Image CI

on:
  push:
    branches: [ "main" ]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout Code
        uses: actions/checkout@v4

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Build and Push Multi-Platform Image
        run: |
          docker buildx build \
            --platform linux/amd64,linux/arm64 \
            -t yourusername/yourimage:latest \
            --push .

Set your Docker Hub credentials as GitHub Secrets named DOCKER_USERNAME and DOCKER_PASSWORD.

4. Inspect Image Platform Support

Check what platforms your Docker image supports:

docker buildx imagetools inspect yourusername/yourimage:latest

Bonus: Clean Up

Clean unused resources:

docker system prune -af          # Remove all unused data
docker builder prune             # Clean up Buildx cache

Final Thoughts

Docker Buildx is a must-have tool for modern DevOps workflows. Whether you’re building locally or automating in CI/CD, it ensures your images are compatible across different environments.

If you want your Docker images to “just work” anywhere — use Buildx!

Quick Reference

# Enable Buildx
docker buildx create --use

# Multi-arch build & push
docker buildx build \
  --platform linux/amd64,linux/arm64 \
  -t your/image:latest \
  --push .

# Inspect the image
docker buildx imagetools inspect your/image:latest