Pulumi
Pulumi Corporation
Terraform
HashiCorp (IBM)
You have settled on infrastructure as code. Now you have to pick the tool your team will live in for the next few years. Terraform, created by HashiCorp, is the most widely adopted IaC provisioning tool and defines infrastructure in the purpose-built HashiCorp Configuration Language (HCL). Pulumi takes a code-first approach, letting you define infrastructure in general-purpose languages you may already know — TypeScript, Python, Go, C# and Java.
Key takeaways
- Terraform uses HCL; Pulumi uses TypeScript, Python, Go, C#, Java or YAML.
- Terraform's core moved to the Business Source License (BSL 1.1) from v1.6; Pulumi's core stays under Apache 2.0. The community fork OpenTofu remains MPL 2.0.
- Terraform's registry lists 4,800+ providers; Pulumi maintains ~1,800 packages and can bridge Terraform/OpenTofu providers.
- Pulumi encrypts secrets by default and supports native language testing; Terraform relies on external tools like Terratest and Vault.
- HashiCorp deprecated and archived CDKTF on 2025-12-10, removing the official general-purpose-language path for Terraform.
Quick verdict · Depends on team skills and licensing constraints
Winner: Depends
There is no universal winner. Terraform wins on provider breadth and adoption; Pulumi wins on language flexibility, testing and developer experience. Licensing may be the deciding factor for some teams.
Choose Pulumi if
Choose Terraform if
Rule of thumb
Scorecard
Terraform leads on ecosystem breadth and adoption; Pulumi leads on language flexibility, testing and secrets handling. Scores reflect the public documentation and the dimensions that matter in practice.
| Criterion | Pulumi | Terraform | Winner |
|---|---|---|---|
| Language & flexibility | 9.2/10 | 6.5/10 | Pulumi |
| Provider ecosystem | 8/10 | 9.3/10 | Terraform |
| Testing | 9/10 | 6/10 | Pulumi |
| Developer experience & IDE | 9/10 | 7/10 | Pulumi |
| Secrets management | 8.5/10 | 6/10 | Pulumi |
| Adoption & community | 7/10 | 9.5/10 | Terraform |
| Open-source licensing | 9/10 | 6/10 | Pulumi |
Head-to-head
Language support
PulumiHow each tool lets you express infrastructure.
Pulumi
Pulumi supports general-purpose languages including TypeScript, JavaScript, Python, Go, C# and Java (plus YAML), letting you use loops, conditionals, functions and classes natively. Pulumi can also convert HCL configurations into Pulumi programs and can run existing Terraform/HCL configurations directly, easing adoption.
Terraform
Terraform uses HCL, a JSON-compatible, purpose-built configuration language with dedicated syntax for constructs like conditionals and loops. HashiCorp previously offered CDKTF to define infrastructure in TypeScript, Python, Go, Java or C#, but deprecated and archived it on 2025-12-10, so the official general-purpose-language path is gone.
Verdict
IDE features
PulumiEditor tooling and developer ergonomics.
Pulumi
Because Pulumi uses common programming languages, you get the rich IDE integration of your chosen language — code completion, strong typing, IntelliSense, debugging, linting and refactoring.
Terraform
Terraform has well-supported IDE plugins (for example in VS Code) offering autocomplete and linting, but tooling is limited to the plugin's capabilities.
Verdict
Open-source licensing
PulumiLicense terms and their implications.
Pulumi
Pulumi's core remains under the Apache License 2.0, with commercial SaaS tiers layered on top.
Terraform
Terraform used MPL 2.0 through v1.5; in August 2023 HashiCorp relicensed it under the Business Source License (BSL 1.1), which restricts competitor use without an agreement. HashiCorp is now part of IBM (acquisition completed February 2025). The relicensing prompted OpenTofu, an MPL-licensed, Linux Foundation-governed fork.
Verdict
Testability
PulumiHow you validate and test infrastructure code.
Pulumi
Pulumi supports native unit and integration testing using language frameworks (for example xUnit for .NET), including tests that mock external calls.
Terraform
Terraform offers plan (preview of changes), validate and format commands for basic validation. Thorough integration and end-to-end testing typically relies on third-party tools like Terratest, a Go library.
Verdict
Cloud provider support
TerraformBreadth and freshness of provider coverage.
Pulumi
Pulumi maintains native providers for AWS, Azure, Google Cloud and Kubernetes with same-day support for new releases, plus a registry of roughly 1,800 packages. It bridges Terraform and OpenTofu providers, so if a Terraform provider exists you can almost always use it from Pulumi.
Terraform
Terraform supports all major clouds and has a large community of custom-provider authors; its registry lists more than 4,800 providers, though new cloud services aren't always available on day one.
Verdict
State management
TieHow each tool tracks the current infrastructure state.
Pulumi
Pulumi stores state in a backend, defaulting to Pulumi Cloud, with self-managed options like Amazon S3, Azure Blob Storage or Google Cloud Storage. Its code-driven model can feel more flexible for developers.
Terraform
Terraform stores state in a file (terraform.tfstate), local by default and usually moved to remote storage such as an Azure blob container for backup, recovery and team collaboration via shared state.
Verdict
Secrets management
PulumiHow sensitive values are protected.
Pulumi
Pulumi encrypts secrets by default and integrates with KMS providers.
Terraform
Terraform's built-in secrets handling is basic and manual; teams typically pair it with HashiCorp Vault.
Verdict
Kubernetes support
PulumiHow each tool provisions and manages Kubernetes.
Pulumi
Pulumi supports Kubernetes natively via YAML, Helm and programmatic APIs.
Terraform
Terraform manages Kubernetes through its Kubernetes provider using HCL configuration.
Verdict
Feature matrix
| Feature | Pulumi | Terraform | Winner |
|---|---|---|---|
| General-purpose language support · Language | TypeScript, Python, Go, C#, Java, YAML. | HCL DSL and JSON; CDKTF deprecated/archived 2025-12-10. | Pulumi |
| Full IDE tooling (debug, lint, refactor) · Developer experience | Inherited from chosen language. | Via extensions (autocomplete, linting). | Pulumi |
| Apache 2.0 core license · Licensing | Apache 2.0 core, commercial SaaS tiers. | BSL 1.1 from v1.6; MPL 2.0 up to v1.5. | Pulumi |
| Built-in unit & integration testing · Testing | Native language frameworks with mocking. | plan/validate plus external tools (Terratest). | Pulumi |
| Provider ecosystem breadth · Ecosystem | ~1,800 packages; bridges Terraform/OpenTofu providers. | 4,800+ providers in registry. | Terraform |
| Secrets encrypted by default · Security | Encrypted by default, KMS integrations. | Basic/manual; typically paired with Vault. | Pulumi |
| Native Kubernetes (YAML/Helm/APIs) · Kubernetes | Native YAML, Helm, programmatic APIs. | Via Kubernetes provider (HCL). | Pulumi |
| Preview of changes before apply · Workflow | Diff-based preview. | Execution plans (plan). | Tie |
| Run existing Terraform/HCL directly · Migration | Can run existing Terraform/HCL and convert HCL to Pulumi programs. | - N/A. | Pulumi |
Pricing
Both tools have free open-source cores and commercial cloud/SaaS tiers. Pulumi's core is Apache 2.0 with Pulumi Cloud SaaS tiers; Terraform's core (BSL from v1.6) has HashiCorp Cloud/Enterprise offerings. Exact pricing varies by tier and usage — verify on each vendor's pricing page.
| Pulumi | Terraform | |
|---|---|---|
| Model | Open-source core (Apache 2.0) plus Pulumi Cloud SaaS tiers. | Open-source CLI (BSL 1.1 from v1.6) plus HashiCorp Cloud/Enterprise commercial tiers. |
Pricing is mixed (checked July 1, 2026).
Pricing tiers and limits change; confirm current figures on the vendors' pricing pages before budgeting. OpenTofu is a free, MPL-licensed alternative to the Terraform CLI.
Best for each use case
| Use case | Pick | Why |
|---|---|---|
| Developer-heavy team already fluent in TypeScript/Python/Go/C# · Application/platform engineering teams | Pulumi | Writing infrastructure in a known language with full IDE and testing tooling reduces friction.Requires comfort maintaining application-grade code for infrastructure. |
| Maximum provider coverage across many niche services · Multi-cloud platform teams | Terraform | Terraform's 4,800+ provider registry is the broadest.Pulumi can bridge Terraform providers, narrowing the gap. |
| Strong testing and CI/CD discipline for infrastructure · Teams with mature CI/CD practices | Pulumi | Native unit/integration tests with mocking fit software engineering workflows. |
| Avoiding BSL licensing restrictions with open source · Vendors and orgs sensitive to BSL terms | Depends | Pulumi's core is Apache 2.0; OpenTofu (an MPL fork of Terraform) is the open-source Terraform-compatible route.OpenTofu, not Terraform, is the MPL-licensed option. |
| Hiring for the most common industry IaC skill · Organizations optimizing for staffing | Terraform | Terraform/HCL has the widest adoption and hiring pool. |
Pros & cons
Pulumi
- Strengths
- Write infrastructure in TypeScript, Python, Go, C#, Java or YAML.
- Full IDE tooling: debugging, linting, refactoring, IntelliSense.
- Native unit and integration testing with mocking.
- Secrets encrypted by default with KMS integrations.
- Apache 2.0 core license.
- Can run existing Terraform/HCL directly and bridge Terraform/OpenTofu providers.
- Native Kubernetes support via YAML, Helm and programmatic APIs.
- Trade-offs
- Smaller native provider registry (~1,800 packages) than Terraform.
- Requires developers comfortable maintaining general-purpose code.
- Smaller community and hiring pool than Terraform.
Pulumi is the code-first choice: strongest for teams that want real programming languages, testing and modern developer tooling.
Terraform
- Strengths
- Largest provider ecosystem (4,800+ providers).
- Most widely adopted IaC tool with the biggest community and hiring pool.
- Simple, declarative HCL DSL that is easy to read.
- Mature execution plans to preview changes before apply.
- Flexible remote/local state backends.
- Trade-offs
- HCL is a DSL with limited programming constructs compared with full languages.
- Core relicensed to BSL 1.1 from v1.6, restricting competitor use.
- CDKTF deprecated and archived on 2025-12-10, removing the general-purpose-language path.
- Basic secrets handling; typically needs Vault.
- Thorough testing relies on external tools like Terratest.
Terraform is the ecosystem and adoption leader with a simple DSL, but licensing changes and limited testing/secrets features push some teams to alternatives.
Decision guide
Choose Pulumi when
- Your team already writes TypeScript, Python, Go, C# or Java.
- You want native unit/integration testing for infrastructure.
- You need secrets encrypted by default.
- An Apache 2.0 core license matters to you.
Choose Terraform when
- You need the broadest possible provider coverage.
- You want the most common industry IaC skill for hiring.
- You prefer a simple declarative DSL over full code.
Choose neither when
- You want a pure GUI, no-code infrastructure workflow.
Choose based on team skills, ecosystem needs and licensing tolerance. Developer-heavy teams gain most from Pulumi; teams optimizing for provider breadth and industry-standard skills lean Terraform (or OpenTofu).
Migration — Both use a desired-state model with local and remote backends; state can be self-hosted (S3, Azure Blob, GCS) in either tool.
Security & compliance
PulumiPulumi encrypts secrets by default and integrates with KMS providers; Terraform's built-in secrets handling is basic and typically paired with HashiCorp Vault.
Both support version-controlled configurations enabling code review and audit of infrastructure changes. Specific certifications should be verified on each vendor's trust/security pages.
Performance & scalability
Both tools use a desired-state model, comparing declared state against current state to compute the resources to create, update or delete. Practical performance depends more on provider behavior and state backend than on the tool itself.
Both scale to large multi-cloud estates and integrate into CI/CD pipelines; Terraform's larger provider ecosystem and Pulumi's code-based reuse (functions, classes) each help at scale in different ways.
Alternatives
OpenTofu · Linux Foundation
An MPL 2.0-licensed community fork of Terraform created after the BSL relicensing.
Why consider — Drop-in open-source alternative to the Terraform CLI governed by the Linux Foundation.
VisitAWS CloudFormation · Amazon Web Services
AWS-native IaC service using JSON/YAML templates.
Why consider — Deep native AWS integration without third-party tooling.
VisitAWS CDK · Amazon Web Services
Define AWS infrastructure in general-purpose languages, synthesized to CloudFormation.
Why consider — Similar code-first philosophy to Pulumi but AWS-centric.
VisitFrequently asked questions
What is the main difference between Pulumi and Terraform?
Terraform defines infrastructure in HCL, a purpose-built configuration language, while Pulumi lets you write infrastructure in general-purpose languages like TypeScript, Python, Go, C# and Java. This shapes testing, IDE tooling and code reuse.
Is Pulumi open source?
Pulumi's core is licensed under Apache 2.0, with commercial Pulumi Cloud SaaS tiers layered on top.
Why did Terraform's license change?
Terraform used MPL 2.0 through v1.5. In August 2023 HashiCorp relicensed it under the Business Source License (BSL 1.1) from v1.6, which restricts competitor use without an agreement. This prompted the community to create OpenTofu, an MPL-licensed fork governed by the Linux Foundation. HashiCorp is now part of IBM.
Can Pulumi use existing Terraform code?
Yes. Pulumi can run existing Terraform and HCL configurations directly and can convert HCL into Pulumi programs, so teams can adopt Pulumi without rewriting their Terraform code up front. Pulumi also bridges Terraform and OpenTofu providers.
Which has more provider support?
Terraform's registry lists more than 4,800 providers, larger than Pulumi's roughly 1,800 packages. However, Pulumi maintains native providers for the major clouds and Kubernetes with same-day support, and bridges Terraform/OpenTofu providers to close the gap.
How do they handle secrets?
Pulumi encrypts secrets by default and integrates with KMS providers. Terraform's built-in secrets handling is basic and manual, so teams typically pair it with HashiCorp Vault.
What happened to CDKTF?
CDKTF (Cloud Development Kit for Terraform) let you define infrastructure in TypeScript, Python, Go, Java or C# and synthesize it to Terraform configuration. HashiCorp deprecated and archived it on 2025-12-10, so it is no longer maintained.
Final verdict
Terraform is the most widely adopted IaC tool, with the largest provider registry (4,800+) and a simple declarative HCL DSL. Pulumi takes a code-first approach with general-purpose languages, native testing, full IDE tooling and secrets encrypted by default, all on an Apache 2.0 core. Licensing (Terraform's BSL vs Pulumi's Apache 2.0) and the deprecation of CDKTF are meaningful factors in 2026.
There is no universal winner. Match the tool to your team's language skills, ecosystem needs and licensing constraints.
Pulumi is best for
Terraform is best for
