On-Premises Agents vs Microsoft-Hosted Agents in Azure DevOps: What is the Difference?

In today’s DevOps-driven development landscape, automation and continuous delivery are critical. One of the most essential pieces in this pipeline is the build agent — a machine responsible for executing tasks like building code, running tests, and deploying applications. In Azure DevOps, there are two primary types of agents: Microsoft-hosted agents and self-hosted (on-premises) agents.

This blog explores what each type offers, how they differ, when to use them, and which scenarios benefit from one over the other.

🚀 What Are Azure DevOps Agents?

Agents are computing infrastructure used to run your CI/CD jobs. They process build and release pipeline tasks defined in your YAML or classic pipeline.

You have two choices:

• Microsoft-hosted agents (cloud-based)
• Self-hosted agents (on-premise or cloud VM-based)

Microsoft-Hosted Agents

Microsoft provides pre-configured virtual machines with commonly used tools and SDKs installed (like .NET, Node.js, Python, PowerShell, Docker, etc.).

Benefits:

• No setup required — ready to use
• Updated weekly with latest tools and OS patches
• Auto-scaled — great for distributed teams
• Good for short and simple builds

Limitations:

• Limited concurrency on free tier
• Ephemeral agents — new machine for every run
• No customization of tools or OS
• No access to internal systems or secure resources

Self-Hosted (On-Premise) Agents

These are agents you set up and maintain yourself — either on your local data center or cloud-hosted virtual machines.

Benefits:

• Full control over tools, versions, and OS
• Persistent environments — useful for caching
• Secure resource access (databases, internal APIs)
• No build time limits

Limitations:

• You manage updates and maintenance
• Scaling requires manual provisioning
• Security and availability are your responsibility

Key Differences at a Glance

When to Use Which?

Use Microsoft-hosted agents when:

• You want quick setup
• You run public or open-source projects
• You don’t need special tools or private network access

Use Self-hosted agents when:

• You need access to internal systems
• You require custom tools or older SDKs
• You want faster builds using persistent caching
• You have strict security or compliance requirements

Setting Up a Self-Hosted Agent

Here’s a brief look at how to configure a self-hosted agent on a Windows machine:

1. Go to Azure DevOps > Project Settings > Agent Pools
2. Click Add agent
3. Choose your OS and download the agent
4. Extract and run config.cmd to register
5. Run the agent as a service using svc install and svc start

Final Thoughts

Choosing between Microsoft-hosted and self-hosted agents depends on your team’s needs for speed, control, security, and scalability. While Microsoft-hosted agents are ideal for getting started quickly, self-hosted agents offer the flexibility and control necessary for enterprise-level workflows or hybrid environments.

By understanding the trade-offs, you can design pipelines that are both efficient and tailored to your infrastructure.