HCL to JSON

About this tool

HashiCorp Configuration Language is pleasant to write by hand, but many scripts and review tools want JSON. This converter parses HCL2 — the syntax used by Terraform .tf and .tfvars files, plus Packer, Nomad, Vault, and Consul configs — and renders the equivalent JSON document locally in your browser.

Attributes become JSON properties. Blocks become nested objects keyed by the block type and then by each quoted label. If the same block header appears more than once, that spot becomes a JSON array. Expressions JSON cannot represent, such as var.region, upper("x"), or var.enabled ? 1 : 0, are preserved as Terraform-style ${...} strings so they are visible instead of being dropped.

Worked example

Input HCL:

resource "aws_instance" "web" {
  ami           = "ami-0123456789"
  instance_type = "t3.micro"
  monitoring    = true
  tags = {
    Name = "web"
    Env  = "prod"
  }
}

Default JSON output:

{
  "resource": {
    "aws_instance": {
      "web": {
        "ami": "ami-0123456789",
        "instance_type": "t3.micro",
        "monitoring": true,
        "tags": {
          "Name": "web",
          "Env": "prod"
        }
      }
    }
  }
}

Options

• Block shape — nested keeps single block bodies as objects and uses arrays only for repeated block headers. arrays always wraps block bodies in arrays, which is convenient for scripts that want one stable shape.
• Expression handling — template preserves non-JSON expressions as ${...} strings. simplify first evaluates constant expressions, so 1 + 2 becomes 3, while unknown variables still remain as ${var.name}.
• Pretty print and indent — choose human-readable output with two spaces, four spaces, or tabs, or turn pretty printing off for compact single-line JSON.
• Sort keys — alphabetize object keys at every level for cleaner diffs.

Limits and edge cases

• Input is capped at 1,048,576 bytes to keep browser and command-line runs predictable.
• Comments are parsed and then dropped because JSON has no comment syntax.
• HCL expressions are not evaluated against Terraform variables, providers, functions, or files. Unknown expressions are represented as strings instead.
• Duplicate attributes are rejected by the HCL parser; using the same name as both an attribute and a block produces a clear conflict error.
• The output is a structural JSON equivalent of one pasted file, not a Terraform plan, state file, provider schema expansion, or module loader.

FAQ