How to Parse YAML in JavaScript

Install js-yaml

npm install js-yaml

Parse a YAML String

import jsyaml from 'js-yaml';

const yamlString = `
name: Alice
age: 30
skills:
  - JavaScript
  - YAML
  - Node.js
`;

const data = jsyaml.load(yamlString);
console.log(data);
// { name: 'Alice', age: 30, skills: ['JavaScript', 'YAML', 'Node.js'] }

Read a YAML File in Node.js

import fs from 'fs';
import jsyaml from 'js-yaml';

const config = jsyaml.load(fs.readFileSync('config.yaml', 'utf8'));
console.log(config.name);

Dump JavaScript Object to YAML

import jsyaml from 'js-yaml';

const data = { name: 'Alice', age: 30, skills: ['JavaScript', 'YAML'] };

const yaml = jsyaml.dump(data, {
  indent: 2,
  lineWidth: -1,   // no line wrapping
  noRefs: true     // no YAML references/aliases
});
console.log(yaml);

Use js-yaml in the Browser

<!-- Load from CDN -->
<script src="https://cdn.jsdelivr.net/npm/js-yaml@4/dist/js-yaml.min.js"></script>
<script>
  const data = jsyaml.load('name: Alice\nage: 30');
  console.log(data); // { name: 'Alice', age: 30 }
</script>

Convert YAML to JSON

import jsyaml from 'js-yaml';

const yamlString = `name: Alice\nage: 30`;
const data = jsyaml.load(yamlString);
const json = JSON.stringify(data, null, 2);
console.log(json);

Need to format YAML without writing code?

Paste any YAML into the free online formatter — instant results, no setup needed.

Frequently Asked Questions