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Formatters

Convert YAML to JSON

YAML to JSON converter parses the YAML you paste with the js-yaml parser and prints it as JSON, indented four spaces per nesting level by default ("Indent" also offers 2 spaces or a tab). Developers use it to read CI configuration, docker-compose files and Kubernetes manifest snippets as JSON, and to hand YAML-written config to tools that only accept JSON. Anchors and aliases resolve to their full values, YAML numbers such as 1.0 serialize as 1, unquoted date-like scalars become UTC timestamp strings, and a file with several --- documents becomes a JSON array.

Open YAML to JSON in the app Browse all tools

How to use YAML to JSON

  1. Open YAML to JSON in the Toolbox101 app.
  2. Paste the YAML into the YAML box; a config block or manifest snippet works.
  3. Pick Indent: 2 spaces, 4 spaces (the default) or Tab.
  4. Read the JSON in the Output box, with keys in document order. Aliases such as *base expand to their full value.
  5. Click Copy to put the JSON on your clipboard.

Worked example

YAML to JSON returns the output below for this input.

Input

name: toolbox101
version: 1.0
enabled: true
replicas: 3
ports:
  - 8080
  - 9090
env:
  NODE_ENV: production

Output

{
    "name": "toolbox101",
    "version": 1,
    "enabled": true,
    "replicas": 3,
    "ports": [
        8080,
        9090
    ],
    "env": {
        "NODE_ENV": "production"
    }
}

Check it yourself: open YAML to JSON and enter the same input.

Frequently asked questions

Are YAML anchors and aliases resolved?

Yes. An anchor such as &defaults and an alias such as *defaults are resolved while parsing, so the JSON repeats the anchored content at every alias instead of keeping the reference. Merge keys written with << are expanded the same way.

Why did my YAML value 1.0 become 1 in the JSON?

In YAML an unquoted 1.0 is a number, and JavaScript serializes the float 1.0 as 1 because JSON has no separate notation for a whole number. Quote the value, for example version: '1.0', if you need the string form preserved in the output.

Why did an unquoted date become a UTC timestamp string?

The js-yaml parser recognizes date-like scalars such as 2024-01-02 and converts them to UTC dates, so the JSON shows the ISO 8601 form ending in Z. Quote the value if you want the literal text kept instead of a parsed timestamp.

Can it convert a YAML file with multiple documents?

Yes. A stream with several documents separated by --- lines comes out as a JSON array with one element per document. A file with a single document is converted on its own, not wrapped in an array.

Use YAML to JSON now

Open YAML to JSON in the app

Runs in your browser. Nothing you type is uploaded.