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JSON / YAML Formatter

Format and convert JSON and YAML instantly

A 2,000-character minified JSON blob on a single line. A docker-compose.yml that refuses to parse because of a stray space. Paste your content below: formatting, conversion, and validation in one click.

Select operation

JSON pretty-print & minify

Indent compact JSON for readability, or minify it to reduce size. Choose 2-space or 4-space indentation.

JSON to YAML

Convert a JSON payload to clean YAML. Ideal for transforming API configs into Kubernetes or Docker Compose files.

YAML to JSON

Transform YAML into valid JSON. Perfect for injecting a YAML config into a REST API call.

Built-in validation

The JSON/YAML Formatter validates syntax on the fly and returns explicit errors. If your document contains an error, you'll know immediately.

100% free and private

No signup required. Your data is not stored. Processing happens via the API and data is deleted after the response.

Why format JSON or YAML?

If you work with REST APIs or CI/CD pipelines, you handle JSON and YAML multiple times a day. A compact JSON payload copied from an API response is unreadable; a poorly indented YAML file breaks a Kubernetes deployment. Minifying JSON reduces payload size by 30–60% by stripping whitespace and line breaks.

Three common use cases:

  • API debugging → Pretty-print a minified JSON payload to inspect fields and spot errors
  • Config conversion → Convert JSON to YAML for a docker-compose.yml or a Kubernetes manifest
  • Quick validation → Check whether a JSON or YAML document contains syntax errors

How to use the JSON / YAML Formatter in 3 steps

Step 1: Paste your content

Paste your JSON or YAML into the input area. The tool accepts documents up to 1 MB.

Step 2: Choose the operation

Select the appropriate mode:

  • Format JSON: pretty-print with 2-space indentation (default), or minify
  • JSON → YAML: full conversion to YAML
  • Format YAML: normalize YAML indentation
  • YAML → JSON: conversion to indented JSON

Step 3: Get the result

Click "Format / Convert". The output appears in the result area. Copy it directly.

What are JSON and YAML?

JSON (JavaScript Object Notation, RFC 8259) is a structured text format (objects, arrays, scalars). It's the standard for REST APIs, configuration files, and data exchange.

YAML (YAML Ain't Markup Language, spec 1.2) is a superset of JSON that's more readable thanks to indentation. It's the standard for Kubernetes configs, Docker Compose, GitHub Actions, GitLab CI, and Ansible. Any valid JSON is also valid YAML.

Conversion example:

{
  "name": "captaindns.com",
  "records": [
    {"type": "A", "value": "93.184.216.34"},
    {"type": "MX", "value": "mail.captaindns.com"}
  ]
}

Converted to YAML:

name: captaindns.com
records:
  - type: A
    value: 93.184.216.34
  - type: MX
    value: mail.captaindns.com

What operations does the tool support?

OperationInputOutputTypical use
Format JSONCompact or poorly indented JSONIndented JSON (2 or 4 spaces) or minifiedAPI debugging, readability
JSON → YAMLValid JSONFormatted YAMLCreate a docker-compose, K8s manifest
Format YAMLYAML with inconsistent indentationNormalized YAMLClean up a config before committing
YAML → JSONValid YAMLIndented or minified JSONPrepare an API payload from a YAML config

Real-world use cases

Scenario 1: Debug an API response

Symptom: You receive a 500-character minified JSON payload on a single line. Diagnosis: Paste the JSON and select "Format JSON". Action: The JSON is indented and readable. Identify the faulty field in seconds.

Scenario 2: Convert Terraform output to YAML

Symptom: You have JSON output from terraform output -json and need to integrate it into a YAML file. Diagnosis: Paste the JSON and select "JSON → YAML". Action: Copy the generated YAML directly into your config file.

Scenario 3: Validate a docker-compose.yml

Symptom: A docker compose up fails with a parsing error. Diagnosis: Paste the YAML and select "Format YAML". If the YAML is invalid, the tool reports the error. Action: Fix the identified error and re-run the deployment.

❓ FAQ - Frequently asked questions

Q: What is the maximum size accepted?

A: The tool accepts JSON or YAML documents up to 1 MB. For larger files, use jq (JSON) or yq (YAML) on the command line.

Q: Does the tool validate JSON syntax?

A: Yes. If the JSON is invalid, the tool returns an explicit error (ERR_INVALID_JSON_INPUT) with a descriptive message.

Q: What is the difference between JSON and YAML?

A: JSON uses braces, quotes, and commas. YAML uses indentation and is more human-readable. YAML is a superset of JSON.

Q: What does minifying JSON mean?

A: Minifying removes all unnecessary whitespace and line breaks to produce a compact single-line JSON.

Q: How does the tool handle non-string keys in YAML?

A: YAML allows numeric or boolean keys (true: value, 42: data). When converting to JSON, they are automatically converted to strings.

Q: Is my data stored?

A: No. Content is processed in memory and deleted immediately after the response.

Q: Can I use this tool to validate a Kubernetes file?

A: The tool validates YAML syntax, not the Kubernetes schema. Use kubectl apply --dry-run for schema validation.

Complementary tools

ToolPurpose
Base64 Encoder / DecoderEncode JSON payloads to Base64 for transport
URL Encoder / DecoderEncode JSON in a URL query string
Regex TesterExtract values from JSON using regular expressions
Hash GeneratorCompute a hash of a JSON document for integrity checks

Useful resources