Are YAML anchors and aliases supported?

Yes. Anchors (&name), aliases (*name) and merge keys (<<) are resolved, so the JSON contains the full data.

What happens to YAML comments?

JSON has no comments, so they are dropped. The data itself is converted completely.

What if the YAML file has several documents?

Documents separated by --- become a JSON array with one entry per document.

Which YAML version is used?

YAML 1.2, the current version. In YAML 1.2, yes and no are strings, not booleans; use true and false for booleans.

YAML to JSON Converter

Convert YAML configs and manifests to JSON, with anchors and aliases resolved.

YAML input

# Kubernetes deployment
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
  labels: &labels
    app: web
    tier: frontend
spec:
  replicas: 3
  selector:
    matchLabels: *labels
  template:
    spec:
      containers:
        - name: web
          image: nginx:1.27
          ports:
            - containerPort: 80
          env:
            - name: GREETING
              value: "Hello, world"

JSON output

{
  "apiVersion": "apps/v1",
  "kind": "Deployment",
  "metadata": {
    "name": "web",
    "labels": {
      "app": "web",
      "tier": "frontend"
    }
  },
  "spec": {
    "replicas": 3,
    "selector": {
      "matchLabels": {
        "app": "web",
        "tier": "frontend"
      }
    },
    "template": {
      "spec": {
        "containers": [
          {
            "name": "web",
            "image": "nginx:1.27",
            "ports": [
              {
                "containerPort": 80
              }
            ],
            "env": [
              {
                "name": "GREETING",
                "value": "Hello, world"
              }
            ]
          }
        ]
      }
    }
  }
}

{
  "apiVersion": "apps/v1",
  "kind": "Deployment",
  "metadata": {
    "name": "web",
    "labels": {
      "app": "web",
      "tier": "frontend"
    }
  },
  "spec": {
    "replicas": 3,
    "selector": {
      "matchLabels": {
        "app": "web",
        "tier": "frontend"
      }
    },
    "template": {
      "spec": {
        "containers": [
          {
            "name": "web",
            "image": "nginx:1.27",
            "ports": [
              {
                "containerPort": 80
              }
            ],
            "env": [
              {
                "name": "GREETING",
                "value": "Hello, world"
              }
            ]
          }
        ]
      }
    }
  }
}

How to convert YAML to JSON

Paste YAML on the left, or open or drop a .yaml or .yml file.
The JSON appears on the right as you type.
If the YAML has an error, it's shown with its line and highlighted.
Copy the JSON or download it as a .json file.

Full YAML support, not just the basics

Real-world YAML uses more than keys and lists. The converter uses a complete YAML 1.2 parser, so anchors (&defaults), aliases (*defaults), merge keys (<<), block strings and multiple documents are all resolved into plain JSON.

YAML

defaults: &defaults
  retries: 3
prod:
  <<: *defaults
  url: https://api.example.com

JSON

{
  "defaults": { "retries": 3 },
  "prod": { "retries": 3, "url": "https://api.example.com" }
}

Use cases

Read Kubernetes, Docker Compose or CI config in code that expects JSON.
Convert an OpenAPI spec from YAML to JSON for tools that need JSON.
Debug what a YAML file actually contains after anchors are resolved.

Related YAML and JSON tools

Convert back with JSON to YAML. If the YAML won't parse, the YAML validator explains why. Afterwards, sort or tidy the JSON with the JSON formatter, or convert spreadsheet data with CSV to JSON.

Frequently asked questions

Are YAML anchors and aliases supported?: Yes. Anchors (&name), aliases (*name) and merge keys (<<) are resolved, so the JSON contains the full data.
What happens to YAML comments?: JSON has no comments, so they are dropped. The data itself is converted completely.
What if the YAML file has several documents?: Documents separated by --- become a JSON array with one entry per document.
Which YAML version is used?: YAML 1.2, the current version. In YAML 1.2, yes and no are strings, not booleans; use true and false for booleans.