YAML to JSON Converter

YAML is pleasant to write but easy to get subtly wrong: one misplaced space changes the structure. Converting it to JSON shows exactly how a parser understands your file, and gives you JSON for APIs, JavaScript code or tools that do not read YAML. The converter follows the YAML 1.2 core schema used by modern tooling.

1. Paste YAML or drop a .yaml / .yml file.
2. If the YAML is invalid, the error message shows the line where parsing failed.
3. Pick an indentation for the JSON output under Options.
4. Copy the JSON or download it.

Example

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
  labels:
    app: web
spec:
  replicas: 3
  template:
    spec:
      containers:
        - name: nginx
          image: nginx:1.27
          ports:
            - containerPort: 80

{
  "apiVersion": "apps/v1",
  "kind": "Deployment",
  "metadata": {
    "name": "web",
    "labels": {
      "app": "web"
    }
  },
  "spec": {
    "replicas": 3,
    "template": {
      "spec": {
        "containers": [
          {
            "name": "nginx",
            "image": "nginx:1.27",
            "ports": [
              {
                "containerPort": 80
              }
            ]
          }
        ]
      }
    }
  }
}

A Kubernetes manifest becomes nested JSON objects and arrays — exactly the structure the Kubernetes API itself receives, since kubectl converts YAML to JSON before sending it.

YAML rules used by the converter

• YAML 1.2 core schema: only true/false are booleans. Words such as yes, no, on and off stay strings, avoiding the classic YAML 1.1 surprises.
• Dates stay strings such as "2026-10-31" rather than being converted to timestamps.
• Anchors and aliases (&base, *base) and merge keys are expanded into full JSON.
• Multi-document files separated by --- become a JSON array with one element per document.

Common YAML errors

• Tabs for indentation — YAML only allows spaces.
• Inconsistent indentation between sibling keys.
• Missing space after a colon: key:value is a single string, not a key/value pair.
• Unquoted special characters: values starting with @, `, *, &, !, % or containing : or # need quotes.
• Leading zeros: an unquoted 01234 is read as the number 1234 — quote ZIP codes and IDs.

JSON as a YAML debugger

When a deployment or pipeline behaves strangely, converting its YAML to JSON is one of the fastest ways to check the structure. Lists that should be nested but are not, keys that ended up at the wrong level, or a value that became a number instead of a string are immediately visible in the JSON.

Real-world examples

Check what a GitHub Actions workflow really contains

Indentation mistakes in YAML change the meaning silently. The JSON view shows whether steps really sits under the right job.

name: CI
on: [push]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: npm test

{
  "name": "CI",
  "on": [
    "push"
  ],
  "jobs": {
    "test": {
      "runs-on": "ubuntu-latest",
      "steps": [
        {
          "uses": "actions/checkout@v4"
        },
        {
          "run": "npm test"
        }
      ]
    }
  }
}

Feed configuration to a JSON-only API

Many APIs and CLIs accept JSON only. Write the settings comfortably in YAML, with anchors to avoid repetition, and convert before sending.

defaults: &defaults
  timeout: 30
  retries: 3
staging:
  <<: *defaults
  url: https://staging.example.com
production:
  <<: *defaults
  url: https://example.com
  retries: 5

{
  "defaults": {
    "timeout": 30,
    "retries": 3
  },
  "staging": {
    "timeout": 30,
    "retries": 3,
    "url": "https://staging.example.com"
  },
  "production": {
    "timeout": 30,
    "retries": 5,
    "url": "https://example.com"
  }
}

Common errors and how to fix them

Related guides

• JSON Lines (JSONL) explained

Convert YAML to JSON in code

For one-off files the tool above is quickest. To automate the same task in a script or pipeline, these snippets are a good starting point.

Python (PyYAML)

import json
import yaml  # pip install pyyaml

with open("config.yaml", encoding="utf-8") as f:
    data = yaml.safe_load(f)

print(json.dumps(data, indent=2, ensure_ascii=False, default=str))

Command line (yq)

yq -o json '.' config.yaml > config.json

Node.js (js-yaml)

import yaml from "js-yaml";  // npm install js-yaml
const json = JSON.stringify(yaml.load(text), null, 2);

Frequently asked questions

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