JSON to YAML Converter & YAML to JSON

What is a JSON to YAML Converter?

A JSON to YAML converter changes data written in JSON (JavaScript Object Notation) into YAML (YAML Ain't Markup Language) without changing its meaning. Both formats store the same kinds of data: objects, lists, strings, numbers, booleans and null. JSON wraps everything in braces, brackets and quotes. YAML shows structure with indentation, which makes it shorter and easier to read.

This tool also works in the other direction. Paste YAML from a config file and get clean JSON, ready for an API request, a script or a JSON-only tool. It checks your input as it converts, so you find syntax errors before they break a deployment.

How to Use the JSON YAML Converter

1. Choose the direction: JSON to YAML or YAML to JSON.
2. Paste your data into the input box, or upload a .json, .yaml or .yml file.
3. Pick the indentation (2 or 4 spaces) and any options such as sort keys.
4. Read the converted output, fix any error shown with its line and column, then copy or download the result.

JSON to YAML Example

JSON input:

{
  "name": "webtoolskit",
  "version": 2,
  "private": true,
  "tags": ["json", "yaml", "tools"],
  "server": {
    "host": "localhost",
    "port": 8080
  }
}

YAML output:

name: webtoolskit
version: 2
private: true
tags:
  - json
  - yaml
  - tools
server:
  host: localhost
  port: 8080

YAML to JSON Example

YAML input:

# Docker Compose style
services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    environment:
      - MODE=production

JSON output (the comment is removed because JSON has no comments):

{
  "services": {
    "web": {
      "image": "nginx:latest",
      "ports": ["80:80"],
      "environment": ["MODE=production"]
    }
  }
}

JSON vs YAML: Key Differences

Feature	JSON	YAML
Structure	Braces, brackets and commas	Indentation and dashes
Comments	Not supported	Supported with #
Quotes on strings	Always required	Usually optional
Readability	Good for machines	Better for humans
Multiple documents in one file	No	Yes, separated by ---
Anchors and references	No	Yes (& and *)
Parsing speed	Fast and simple	Slower, more complex rules
Common use	APIs, web apps, data exchange	Config files, CI/CD, Kubernetes, Docker Compose

When to Use JSON and When to Use YAML

Use JSON for API requests and responses, browser code and anywhere a strict, simple format matters. Use YAML for files that people read and edit often, such as deployment configs, CI pipelines and app settings, where comments and a clean layout help.

What Is Lost or Changed During Conversion

• Comments: YAML comments are removed when converting to JSON and cannot be brought back.
• Anchors and aliases: They are expanded into full copies of the data.
• Key order and style: The original style (block or inline, quotes) is not preserved. The output uses a consistent format.
• Dates: A value like 2024-01-15 may be read as a date by some YAML parsers. Put it in quotes if it must stay a plain string.
• Very large numbers: JSON in JavaScript loses precision above 9007199254740991. Keep long IDs as strings.
• NaN and Infinity: These are not valid in JSON.

Common YAML Mistakes

• Using tabs: YAML allows only spaces for indentation.
• Inconsistent indentation: Items at the same level must use the same number of spaces.
• Missing space after the colon: key:value is wrong, key: value is correct.
• Unquoted special values: Strings like yes, no, on, off or 1.10 can be read as a boolean or a number by some parsers. Use quotes when you need a string.
• Colons or # inside strings: Wrap the text in quotes, for example "http://example.com".
• Duplicate keys: The same key twice at one level is an error or silently overwritten, depending on the parser.

Common JSON Mistakes

• Trailing comma: A comma after the last item is not allowed.
• Single quotes: JSON needs double quotes for keys and strings.
• Unquoted keys: {name: "A"} is JavaScript, not JSON.
• Comments: // and /* */ are not valid in JSON.

Frequently Asked Questions

How do I convert JSON to YAML?

Paste your JSON into the input box, choose the JSON to YAML direction and the tool converts it instantly. Objects become key-value lines, arrays become lists with a dash, and nesting is shown by indentation.

How do I convert YAML to JSON?

Paste your YAML, choose the YAML to JSON direction and copy the output. If the YAML has a syntax error, the tool shows the line and column so you can fix it.

What is the difference between JSON and YAML?

JSON uses braces, brackets and quotes and does not allow comments. YAML uses indentation, is easier to read, supports comments and is common in configuration files such as Docker Compose, Kubernetes and GitHub Actions. YAML is a superset of JSON in most cases, so valid JSON can usually be read as YAML.

Are comments kept when I convert YAML to JSON?

No. JSON has no comment syntax, so YAML comments that start with # are dropped during conversion. They also cannot be restored when you convert back to YAML.

What happens to YAML anchors and aliases in JSON?

Anchors (&) and aliases (*) are expanded. The referenced data is copied into every place that used the alias, because JSON has no way to point to another value.

Why does my YAML give an indentation error?

YAML does not allow tabs for indentation, only spaces. Also check that items at the same level use the same number of spaces and that there is a space after each colon. The tool shows the line and column of the first problem.

Is this JSON YAML converter free and private?

Yes. The tool is free, needs no signup and runs in your browser using JavaScript. Your data is not sent to our server. Still, avoid pasting real passwords, API keys or production secrets into any online tool.