Terraform, OpenTofu, and Terragrunt in 2026: A Comparative Analysis of Leading Infrastructure as Code Tools

Managing cloud infrastructure through web interfaces often results in inefficiency, inconsistency, and limited auditability. Infrastructure as code (IaC) tools mitigate these challenges by enabling the definition of servers, databases, and networks in plain text files that are version-controlled, reviewable, and reliably redeployable. As of 2026, the most widely adopted tools are Terraform, OpenTofu, and Terragrunt. A clear understanding of each tool’s purpose and strengths is essential for informed decision-making.

Terraform is the most widely recognised IaC tool globally. It utilises HashiCorp Configuration Language (HCL), a domain-specific language for infrastructure, and provides an extensive ecosystem of over 4,000 providers that support major cloud platforms and services. In 2023, HashiCorp transitioned Terraform’s license to the Business Source License (BSL), restricting its use in the development of competing products. Although this change has minimal immediate impact for most organisations managing their own infrastructure, the adoption of BSL introduces significant long-term legal and operational considerations. Organisations must now address potential uncertainties regarding future licensing terms and compliance, particularly as they scale or modify workflows. The more restrictive licensing has raised concerns about vendor lock-in and directly contributed to the emergence of OpenTofu, an open-source alternative. It is therefore critical for teams to evaluate the legal and strategic implications before selecting an IaC tool.

Recommended for teams seeking a large ecosystem, extensive configuration examples, and easier hiring.

OpenTofu is a direct open-source fork of Terraform, maintained by the Linux Foundation and licensed under MPL 2.0. Existing Terraform configurations are compatible with OpenTofu without modification, enabling most teams to migrate rapidly with minimal risk or downtime. For instance, teams managing AWS infrastructure can transition by replacing the Terraform binary with the OpenTofu binary and executing existing configuration files. OpenTofu introduces features not present in Terraform, including built-in state encryption, selective resource exclusion during testing, and a native testing framework. As a result, OpenTofu is increasingly favoured for new projects.

Recommended for teams needing full Terraform compatibility without BSL constraints, and for those starting new projects who prefer a fully open-source solution.

Terragrunt does not serve as a replacement for Terraform or OpenTofu; rather, it functions as a wrapper designed to address distinct challenges. As infrastructure projects expand, configuration files frequently become repetitive and increasingly difficult to maintain, with remote state settings and provider blocks duplicated across modules. Terragrunt mitigates these issues by enabling the definition of shared configuration, efficient management of module dependencies, and automation of tasks before or after deployments. It maintains compatibility with both Terraform and OpenTofu.

Recommended for teams managing large or complex Terraform codebases that need better structure and less repetition, without changing core tools.

For most teams, adopting OpenTofu alongside Terragrunt is recommended. OpenTofu offers an open-source foundation that maintains full compatibility with existing Terraform configurations. Terragrunt introduces the structural enhancements needed for scalable, maintainable codebases.

For organisations already utilising Terraform and unaffected by the BSL license, immediate migration is not necessary. However, evaluating OpenTofu for future adoption is advisable given potential licensing or organisational changes. If existing Terraform implementations present challenges such as configuration sprawl or repetition, integrating Terragrunt can streamline and structure workflows. This strategy enables teams to address maintainability concerns before a full migration to OpenTofu, facilitating a gradual, pragmatic transition.

At ADMCloudtech, we adopted OpenTofu and Terragrunt for our infrastructure earlier this year. Migrating from Terraform to OpenTofu took one day and was seamless. The most significant improvement was a reduction in maintenance overhead. With Terragrunt’s structure, our engineers spend less time on duplicated configuration and more time on valuable work. We now use this stack for most cloud clients and recommend it as the default for new projects. If you are considering a similar move, ADM Cloudtech can share insights, highlight key considerations, and identify where migration adds the most value. We also offer a complimentary toolchain review for organisations evaluating their infrastructure.