Container Registry Comparison

Container registries are essential for modern cloud-native applications.

They store and manage container images, for deployments across cloud services like Kubernetes (AKS, EKS, GKE), serverless functions, and PaaS platforms.

🚀 Overview of Each Container Registry

Each cloud provider offers a managed container registry:

Azure Container Registry (ACR): A fully managed private Docker registry for storing and managing container images, integrated with Azure Kubernetes Service (AKS), App Services, and Functions.
AWS Elastic Container Registry (ECR): A fully managed registry service that integrates with Amazon Elastic Kubernetes Service (EKS), ECS, and Lambda.
GCP Artifact Registry: A next-generation replacement for Google Container Registry (GCR) that supports Docker images and other artifacts like Maven, npm, and Python.

🔥 Feature Comparison: ACR vs. ECR vs. Artifact Registry

Feature	Azure Container Registry (ACR)	AWS Elastic Container Registry (ECR)	GCP Artifact Registry
Fully Managed?	✅ Yes	✅ Yes	✅ Yes
Geo-Replication	✅ Yes (Multi-Region Replication)	❌ No (Separate registries per region)	✅ Yes
Security & IAM	Azure AD + RBAC + Private Link	IAM + VPC Endpoints	IAM + VPC Service Controls
Pricing Model	Based on storage & operations	Based on storage & API calls	Based on storage & requests
Automated Builds	✅ Azure Container Builds	❌ No built-in (Use CodeBuild)	✅ Cloud Build
OCI Support	✅ Yes	✅ Yes	✅ Yes
Kubernetes Integration	AKS	EKS	GKE
Helm Chart Support	✅ Yes	❌ No	✅ Yes
Multi-Cloud Support?	❌ Primarily Azure	❌ Primarily AWS	✅ Works across GCP & hybrid

💰 Pricing Comparison

Each registry charges based on storage and API requests:

Azure Container Registry (ACR) Pricing

Pricing tiers: Basic, Standard, Premium.
Charges for storage and network egress.
Premium supports geo-replication.

AWS Elastic Container Registry (ECR) Pricing

Free tier: 500MB storage per month.
$0.10 per GB per month for additional storage.
Charges for image retrieval and API calls.

GCP Artifact Registry Pricing

$0.10 per GB per month for storage.
Free 500MB per month.
No additional retrieval fees.

🔹 Which is cheapest? If you have small workloads, AWS and GCP offer a free tier, while ACR charges based on usage tiers.

🔒 Security & Authentication

All three registries support secure image storage, IAM, and encryption:

Azure ACR: Uses Azure Active Directory (Azure AD), RBAC, and private endpoints.
AWS ECR: Uses AWS IAM roles, VPC endpoints, and image scanning.
GCP Artifact Registry: Uses Google IAM, VPC Service Controls, and binary authorization.

ACR and GCP Artifact Registry offer geo-replication, while AWS ECR requires setting up multiple registries.

🚀 Use Cases: When to Choose Each Registry?

✅ Use Azure Container Registry (ACR) if:

You’re running Azure Kubernetes Service (AKS).
You need geo-replication for global deployments.
You want Helm chart support for Kubernetes apps.
You’re using Azure Functions or App Services with containers.

✅ Use AWS Elastic Container Registry (ECR) if:

You’re deploying to Amazon EKS, ECS, or Lambda.
You need tight AWS IAM integration.
You prefer a pay-as-you-go model with free storage.

✅ Use GCP Artifact Registry if:

You need multi-cloud or hybrid support.
You’re deploying to Google Kubernetes Engine (GKE).
You store non-container artifacts (e.g., Maven, npm, Python).

🎯 Final Thoughts: Which One Wins?

Category	Best Option
Best for Azure users	Azure Container Registry (ACR)
Best for AWS users	AWS Elastic Container Registry (ECR)
Best for multi-cloud & hybrid	GCP Artifact Registry
Best for global deployments	ACR (Geo-Replication)
Best for cost-conscious users	AWS ECR (Free Tier)

🔥 Verdict:

If you’re deep in Azure, go with ACR.
If you’re all-in on AWS, choose ECR.
If you want multi-cloud flexibility, GCP Artifact Registry is a solid choice.

📌 Key Takeaways

Aspect	Summary
Azure ACR	Best for Azure users, supports geo-replication & Helm charts.
AWS ECR	Best for AWS workloads, integrates with EKS & Lambda.
GCP Artifact Registry