Best Free Terraform and IaC Tools in 2026
Infrastructure as code is the one category on this site where the interesting difference is a licence, not a feature. In 2023 Terraform moved from an open source licence to the Business Source Licence, the community forked it, and the fork became a Linux Foundation project. Everything about choosing a tool in 2026 traces back to that.
For most users the practical effect is nil: the BSL restricts building a competing commercial product, not using Terraform to manage your infrastructure. But it changed who controls the roadmap, and that is why OpenTofu exists and why it matters.
Here is what each tool is, checked August 2026.
Quick comparison
| Tool | Licence | Language | Rating | Reviews |
|---|---|---|---|---|
| OpenTofu | Open source (Linux Foundation) | HCL | not rated | - |
| Terraform | Free CLI, BSL licence | HCL | 4.7 | 160 |
| AWS CDK | Open source | TypeScript, Python, others | not rated | - |
| Terragrunt | Open source | HCL wrapper | not rated | - |
| Pulumi | Free for individuals | TypeScript, Python, Go, others | 4.8 | 28 |
| Spacelift | Free tier: 2 users, 200 resources | Runs your HCL | not rated | - |
Ratings aggregated by Toolradar. Both samples are small, and the fork has none at all, which is worth a note: OpenTofu is two years old and distributed through package managers, so there is no purchase for a directory to index. Its absence says nothing about it.
OpenTofu: the fork that removed the question
OpenTofu is free and open source under the Linux Foundation, and it is a drop-in replacement for Terraform.
Your existing configuration works. Your state works. The migration is genuinely a matter of changing the binary you call, which is the whole point of a fork done properly.
What you get is governance: a foundation rather than a company, no possibility of another licence change, and a roadmap decided in the open. For organisations who were unsettled by 2023, that is the entire argument and it is sufficient.
Feature parity has held, and OpenTofu has shipped things of its own, notably state encryption, which was a longstanding request.
Terraform: still the default, still free to use
Aggregated rating 4.7 across 160 reviews (4.6 on G2, 4.8 on Capterra). Terraform's CLI is free under the BSL, with HCP Terraform offering a free tier for hosted state and runs.
It remains the largest ecosystem: the most providers, the most modules, the most answers when you search an error message. For a team hiring, it is also the thing people already know.
The BSL is widely misunderstood. It prevents you offering a competing commercial Terraform service; it does not prevent you managing your infrastructure with it, at any scale, for free. Almost everyone reading this is unaffected in practice.
Whether that is enough depends on whether you are choosing on today's terms or on who decides tomorrow's.
Pulumi: infrastructure in a real language
Aggregated rating 4.8 across 28 reviews, too thin to weigh. Pulumi is free for individuals, with usage-based team plans.
Pulumi's premise is that infrastructure deserves a general-purpose language rather than a configuration one. You write TypeScript, Python or Go, with loops, functions, types and the testing tools you already use.
For teams whose infrastructure has genuine logic in it, that is a real improvement over HCL's contortions. Types catching a mistake before an apply is a better experience than discovering it during one.
The trade is that a general-purpose language permits general-purpose complexity, and infrastructure code that is clever is infrastructure code nobody wants to touch at 3am.
AWS CDK: the same idea, AWS only
AWS CDK is free and open source.
CDK compiles code in a real language down to CloudFormation. Within AWS, it is excellent: strong abstractions, sensible defaults, and constructs that encode good practice rather than making you rediscover it.
The constraint is in the name. If you are AWS-only and expect to stay that way, that is not a limitation. If you are not, it is disqualifying.
Terragrunt: the wrapper for repetition
Terragrunt is free and open source, and it wraps Terraform or OpenTofu rather than replacing them.
It exists to solve one problem: the same configuration repeated across many environments and accounts, with the copy-paste drift that follows. It keeps the definitions in one place and the variations declarative.
If you have three environments, you probably do not need it. If you have thirty accounts, it is close to essential and the people who use it are emphatic about it.
Spacelift: the free tier for collaboration
Spacelift's free tier covers 2 users and 200 resources, with custom paid plans above.
Spacelift is the layer around the tool rather than the tool: policy enforcement, drift detection, approvals, and a place where runs happen consistently instead of on someone's laptop.
Two hundred resources is a real allowance for a small environment, and the free tier is enough to establish whether managed runs change how your team works.
What free IaC actually costs
State is the thing that will hurt you. The state file is the map between your configuration and reality, and it commonly contains secrets in plain text. Storing it locally means it is on one laptop; storing it in a bucket without encryption and locking means two applies can corrupt it. Remote state with locking and encryption is the first thing to set up, before anything else in this article matters.
Drift accumulates silently. Someone changes a setting in a console during an incident, nobody updates the code, and the next apply either reverts their fix or fails. Detecting drift is what the paid platforms sell; doing it in CI on a schedule is free and most teams never set it up.
Modules are a supply chain. Public modules run code with your cloud credentials. Pin versions, read what you are pulling, and treat a registry module with the same suspicion as any other dependency.
Why the licence change mattered even though it changed nothing for you
It is tempting to dismiss the 2023 licence change as a non-event for ordinary users, and on the letter of it that is correct. The reason it still reshaped the category is worth understanding, because the same pattern is playing out elsewhere.
Infrastructure code is the most locked-in thing a company owns. Your entire estate is described in one tool's language, your team's expertise is in that language, and your modules and providers assume it. That makes the tool a uniquely bad thing to have governed unilaterally, not because anyone expects malice, but because the cost of an unwelcome decision is enormous and your leverage is nil.
The fork removed that exposure rather than fixing a present problem. What OpenTofu sells is not a feature Terraform lacks; it is the guarantee that no single company can change the terms of something you cannot cheaply leave.
That framing is useful beyond this category. When you are evaluating any tool that will hold your configuration, your data or your team's expertise for years, the governance question is a real input rather than an ideological one, and the right time to ask it is before the migration rather than after the announcement.
How to choose
If you are starting fresh or you were unsettled by the licence change, OpenTofu, which is a drop-in replacement under foundation governance.
If you want the largest ecosystem and the licence does not affect you, Terraform, which for almost everyone it does not.
If your infrastructure has real logic and your team writes code, Pulumi, free for individuals.
If you are AWS-only, AWS CDK.
If you repeat the same configuration across many accounts, Terragrunt on top of whichever you chose.
Set up remote state with locking and encryption before you write a second module. Everything else here is a preference; that one is the difference between a bad afternoon and a lost environment.
Related: our guide to free CI/CD tools covers running these in a pipeline, and the Dupple reviews directory has current pricing.
FAQ
Is Terraform still free?
Yes, the CLI is free to use under the Business Source Licence. The BSL prevents you from offering a competing commercial Terraform service; it does not restrict using Terraform to manage your own infrastructure at any scale. Most teams are unaffected in practice.
Should I switch to OpenTofu?
If the governance question matters to you, yes, and the switch is genuinely easy since it is a drop-in replacement that reads your existing configuration and state. If it does not matter to you, Terraform's larger ecosystem is a fair reason to stay.
Is Pulumi better than Terraform?
Better for teams whose infrastructure needs real logic, because loops, types and tests in a familiar language beat HCL's workarounds. Worse if you value the constraint, since a general-purpose language lets people write clever infrastructure code, and clever is not what you want during an incident.
What is the most important thing to set up first?
Remote state with locking and encryption. The state file maps your code to real infrastructure and frequently contains secrets in plain text. Getting this wrong is how teams corrupt an environment or leak credentials, and it is a ten-minute setup.
