Terraform vs Pulumi

Terraform and Pulumi are Infrastructure as Code (IaC) tools that let you define and manage cloud infrastructure declaratively. Terraform uses its own HCL language, while Pulumi lets you write infrastructure in TypeScript, Python, Go, or C#.

Overview

Terraform by HashiCorp uses HCL (HashiCorp Configuration Language) to define infrastructure. It has the largest provider ecosystem with over 3,000 providers covering every major cloud and SaaS platform. Terraform's state management and plan/apply workflow is the industry standard for IaC. Pulumi lets you define infrastructure using general-purpose programming languages — TypeScript, Python, Go, C#, and Java. This means you get loops, conditionals, functions, classes, and package managers for your infrastructure code. Pulumi also supports Terraform providers via a bridge layer.

Key Differences

Language: Terraform's HCL is a domain-specific language that is easy to learn but limited in expressiveness. Pulumi uses real programming languages with full IDE support, type checking, and testing frameworks. State management: Terraform stores state in files or remote backends (S3, Terraform Cloud). Pulumi offers free state management via Pulumi Cloud, or you can use self-managed backends. Both track resource dependencies and drift. Provider ecosystem: Terraform has the larger native provider ecosystem. Pulumi can use most Terraform providers via its bridge, plus has its own native providers for some services. Testing: Pulumi infrastructure can be unit-tested with standard testing frameworks (Jest, pytest, Go test). Terraform testing requires Terratest or the newer terraform test command, which is more limited.

Pricing

Both tools are open-source and free for CLI usage. Terraform Cloud offers a free tier for up to 500 managed resources. Pulumi Cloud is free for individual use with team plans from $50/month.

Verdict

Choose Terraform if you want the most battle-tested IaC tool with the largest community, most learning resources, and broadest provider support. Choose Pulumi if you want to write infrastructure in a language you already know and need complex logic, reusable components, and standard testing.