Terragrunt vs Terramate: Scaling Terraform Code
Both reduce Terraform/OpenTofu duplication at scale: Terragrunt wraps Terraform with DRY config and dependency orchestration; Terramate generates code and orchestrates runs, working alongside plain Terraform.
As Terraform repos grow, duplication and run orchestration become painful. Terragrunt is a mature wrapper providing DRY backend/inputs config and inter-module dependencies. Terramate takes a code-generation and orchestration approach that keeps your Terraform standard and runnable on its own.
| Terragrunt | Terramate | |
|---|---|---|
| Approach | Wrapper around terraform/tofu | Code generation + orchestration |
| Runs Terraform via | Terragrunt CLI | Standard terraform (orchestrated) |
| DRY mechanism | HCL include / inputs | Generated files + stacks |
| Change detection | Limited | Built-in (changed stacks) |
| Maturity | Long-established | Newer, growing |
Where Terragrunt wins
Terragrunt is mature and widely adopted, with proven patterns for DRY backend/provider config, passing inputs, and ordering module applies via dependencies. If you want a battle-tested wrapper and your team already knows it, Terragrunt is a safe, well-documented choice.
Where Terramate wins
Terramate keeps your Terraform as standard Terraform (no wrapper to run it), generates repetitive config, and detects which stacks changed so CI only runs affected ones. For large monorepos that want change-based orchestration and to avoid lock-in to a wrapper CLI, Terramate is appealing.
In CI
Terramate change detection can cut CI time by planning/applying only changed stacks. Terragrunt run-all applies across modules in dependency order. Pick by whether you prefer a wrapper (Terragrunt) or generated standard Terraform plus change-aware orchestration (Terramate).
The verdict
Choose Terragrunt for a mature, well-known DRY wrapper and dependency orchestration; choose Terramate to keep standard Terraform with code generation and changed-stack detection. Both tame large IaC repos.