What is the difference between JSON and YAML?

JSON uses braces {} and brackets [] with strict quotation requirements, while YAML uses indentation for structure. YAML is more human-readable and supports comments, making it preferred for configuration files. JSON is better for data interchange between applications due to its strict format.

Is this JSON to YAML converter free?

Yes, our JSON to YAML converter is completely free with no usage limits. There's no signup required, and your data is processed entirely in your browser without being sent to any server.

Can I convert YAML back to JSON?

Yes! Use our YAML to JSON converter at /yaml-to-json for reverse conversion. Both tools work instantly in your browser.

Does the converter preserve data types?

Yes, our converter accurately preserves all JSON data types including strings, numbers, booleans, null values, nested objects, and arrays in the YAML output.

Can I use this for OpenAPI/Swagger files?

Absolutely. Our converter handles OpenAPI 3.0 and Swagger 2.0 specification files, properly converting the entire API definition structure to YAML format.

Is my data secure when using this converter?

Yes. All conversion happens locally in your browser using JavaScript. Your JSON data is never sent to any server or stored anywhere. Your data remains completely private.

What if my JSON has errors?

The converter validates your JSON before conversion. You'll see a clear error message identifying the problem, such as missing commas, unmatched brackets, or invalid characters.

Can I convert large JSON files?

Yes. The converter runs in your browser and can handle files as large as your browser's memory allows. For extremely large files, consider using command-line tools like yq or jq.

Does the output preserve key order?

Yes. The converter maintains the same key order from your original JSON. Keys appear in the YAML output in the same sequence you provided them.

What indentation does the YAML output use?

The default output uses 2-space indentation, which is the most common YAML style. You can change this to 4 spaces if your project requires it.

CloudFormation JSON to YAML Converter

How to Convert CloudFormation JSON to YAML

Converting AWS CloudFormation templates from JSON to YAML is simple with our free converter. Paste your entire CloudFormation JSON template into the input field, and the tool generates a properly formatted YAML template that AWS CloudFormation accepts.

The conversion preserves every element of your infrastructure definition. Resources, parameters, outputs, conditions, mappings, and metadata all convert exactly. Intrinsic functions like !Ref, !GetAtt, !Sub, and !Join work correctly in the YAML output.

AWS CloudFormation supports both JSON and YAML template formats. You can deploy either format through the AWS Console, CLI, or SDK without modification.

Why Convert CloudFormation to YAML

Improved Readability

CloudFormation templates often contain hundreds of lines. YAML's indentation-based structure makes large templates easier to navigate without counting braces.

Add Comments

JSON doesn't support comments. YAML lets you document why resources exist, what values mean, and when things might change.

Shorter Intrinsic Functions

YAML supports shorthand syntax for CloudFormation functions. Use !Ref instead of {"Fn::Ref": ...}.

Easier Team Reviews

Infrastructure changes in pull requests are easier to review in YAML format. Cleaner syntax helps team members spot modifications.

Adding Comments to Document Infrastructure

YAML with Comments

Resources:
  # Primary application load balancer
  # Handles all incoming traffic from CloudFront
  ApplicationLoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      # Use internal scheme for private subnets
      Scheme: internal

Intrinsic Function Conversion

All CloudFormation intrinsic functions convert with proper YAML syntax:

JSON Syntax	YAML Short Form	YAML Full Form
{"Ref": "X"}	!Ref X	Ref: X
{"Fn::GetAtt": ["X", "Y"]}	!GetAtt X.Y	Fn::GetAtt: [X, Y]
{"Fn::Sub": "..."}	!Sub '...'	Fn::Sub: '...'
{"Fn::Join": [...]}	!Join [...]	Fn::Join: [...]
{"Fn::If": [...]}	!If [...]	Fn::If: [...]
{"Fn::ImportValue": "..."}	!ImportValue ...	Fn::ImportValue: ...

Supported CloudFormation Elements

All CloudFormation template sections convert:

AWSTemplateFormatVersion — Template version declaration
Description — Template description text
Metadata — Template metadata including AWS::CloudFormation::Interface
Parameters — Input parameters with types and constraints
Mappings — Lookup tables for conditional values
Conditions — Conditional logic definitions
Transform — Macros and SAM transforms
Resources — Infrastructure resource definitions
Outputs — Stack output values

CloudFormation YAML Best Practices

Organize Related Resources

Group related resources together with comment headers:

Organized Resources

Resources:
  # ===================================
  # Networking Resources
  # ===================================

  VPC:
    Type: AWS::EC2::VPC
    # ...

  PublicSubnet:
    Type: AWS::EC2::Subnet
    # ...

  # ===================================
  # Compute Resources
  # ===================================

  WebServer:
    Type: AWS::EC2::Instance
    # ...

Use YAML Anchors for Repeated Values

YAML anchors reduce duplication in templates:

YAML Anchors

Parameters:
  Environment:
    Type: String
    Default: &defaultEnv production  # Define anchor

Resources:
  MyBucket:
    Type: AWS::S3::Bucket
    Properties:
      Tags:
        - Key: Environment
          Value: *defaultEnv  # Reference anchor

CloudFormation Conversion Example

Input: JSON Template

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": "Simple S3 bucket",
  "Parameters": {
    "BucketName": {
      "Type": "String"
    }
  },
  "Resources": {
    "MyBucket": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "BucketName": {"Ref": "BucketName"}
      }
    }
  },
  "Outputs": {
    "BucketArn": {
      "Value": {"Fn::GetAtt": ["MyBucket", "Arn"]}
    }
  }
}

Output: YAML Template

AWSTemplateFormatVersion: '2010-09-09'
Description: Simple S3 bucket

Parameters:
  BucketName:
    Type: String

Resources:
  MyBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Ref BucketName

Outputs:
  BucketArn:
    Value: !GetAtt MyBucket.Arn

Frequently Asked Questions

Does AWS CloudFormation support both JSON and YAML?

Yes. AWS CloudFormation accepts templates in either JSON or YAML format. Both formats are fully supported through the Console, CLI, SDK, and CloudFormation APIs.

Are intrinsic functions converted correctly?

Yes. Intrinsic functions like Ref, Fn::GetAtt, Fn::Sub, Fn::Join, and all others convert to their YAML equivalents. You can use either the short form (!Ref) or long form (Ref:) in YAML.

Can I use the YAML template with AWS SAM?

Yes. AWS SAM (Serverless Application Model) templates use CloudFormation syntax and support YAML format. The converter handles SAM-specific transforms and resource types correctly.

Are nested stacks supported?

Yes. Nested stack references and AWS::CloudFormation::Stack resources convert normally. Template URLs and parameters maintain their values.

What about CloudFormation macros?

Transform declarations for AWS::Include, AWS::Serverless, and custom macros convert correctly. The Transform section maintains its structure in YAML.

Is the conversion reversible?

Yes. You can convert JSON to YAML and back to JSON without losing information. The data structure remains identical in both formats.

Can I convert very large templates?

Yes. The converter runs in your browser and handles templates of any size that your browser's memory can process. CloudFormation templates up to the 1MB AWS limit convert without issues.

CloudFormation JSON to YAML