Convert YAML to JSON

Paste YAML, or drop a .yaml/.yml file, and download it as pretty-printed JSON. Nothing is sent anywhere.

Drop your YAML file here

Choose file

Up to 20MB per file. Stays on this device.

Nothing is sent anywhere. Turn off your Wi-Fi and this page still works - try it.

Or paste YAML

How it works

Drop or choose a .yaml/.yml file, or paste YAML directly into the text box.
Review the pretty-printed JSON preview.
Download the result as a .json file.

Example output

Input

name: Widget
price: 9.5
tags:
  - hardware
  - sale

Output

{
  "name": "Widget",
  "price": 9.5,
  "tags": [
    "hardware",
    "sale"
  ]
}

A single YAML document converted into JSON.

Frequently asked questions

Is my YAML sent anywhere?

No. Pasted YAML and uploaded files are both read and converted entirely on your device, and nothing is sent to a server. Turn off your Wi-Fi after the page loads and it still works. This page loads 10KB of JavaScript, gzipped - about what your browser's network tab will show for this page's own scripts.

What YAML features are supported?

Standard YAML 1.1/1.2 scalars, mappings, sequences, comments, multi-line strings, anchors/aliases, and timestamps (converted to ISO 8601 date strings, the same choice this site’s Excel-to-JSON tool makes for a date cell). Custom application-specific tags aren’t evaluated as code - only plain data comes out, never executable content.

What if my YAML file has more than one document (separated by ---)?

Each document is converted, then combined into a single JSON array in the order they appear. A file with just one document (the common case) converts straight to that document’s own JSON value at the top level, not wrapped in an array.

What happens to YAML’s special numbers like .inf or .nan?

JSON itself has no way to represent infinity or “not a number” - most converters silently turn these into null, quietly losing the original value. This tool writes them out as the visible JSON strings "Infinity", "-Infinity", and "NaN" instead, so nothing disappears without a trace.

What if my YAML has a syntax error?

You’ll get a plain-English error naming the problem and its line and column instead of a converted file. Fix the indentation or syntax at that spot and try again.

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Convert YAML to JSON