JSONLints

Studio
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Ready JSON Ready
1
🌳 Interactive Object Inspector (Click node to expand/collapse)
No valid JSON loaded to display in Tree View.
📊 Tabular View (Auto-detected for arrays of objects)
Table View requires JSON formatted as an array of objects (e.g. [{"id": 1, ...}]).
🔄 Side-by-Side JSON Comparator
Original / Base JSON
Modified / New JSON
// Converted output or generated code will appear here...
📑 JSON Schema Studio Draft-07
JSON Data Payload
JSON Schema (Draft-07)

🌐 What is JSONLints?

JSONLints (JSONLint Studio) is a free, real-time online JSON validator, formatter, beautifier, minifier, and error-repair tool. Built for modern software engineers, it allows developers to quickly inspect complex JSON payloads, debug syntax errors with line-and-column precision, view hierarchical data in an interactive collapsible tree or tabular format, compare differences side-by-side, and convert JSON structures into TypeScript, Python, Go, YAML, CSV, or XML.

🔒 100% Client-Side Privacy

Your data security is paramount. Unlike legacy tools that send your payloads over the internet, JSONLints executes all parsing, linting, and formatting entirely inside your browser (client-side). Your proprietary JSON payloads, API secrets, and tokens never touch an external server.

🛠️ Automatic Syntax Error Repair

Struggling with malformed JSON? Click Auto Repair to automatically fix:

  • Convert single quotes ('key') to standard double quotes ("key")
  • Add missing double quotes around unquoted object keys
  • Strip trailing commas in arrays and objects (e.g. [1, 2, ])
  • Convert Python constants (True, False, None) to valid JSON
  • Strip single-line and multi-line comments (// and /* */)

⚡ Format Converters & Code Generators

Convert validated JSON into developer-ready formats in one click:

  • YAML: Clean, indented YAML configuration files
  • CSV: Flattened tabular data for Excel & Google Sheets
  • XML: Well-formed hierarchical XML documents
  • TypeScript: Strongly-typed interface definitions
  • Python: Type-annotated @dataclass models
  • Go: Struct definitions with JSON struct tags

⌨️ Pro Keyboard Shortcuts

  • Ctrl / Cmd + Enter : Validate & Format JSON
  • Ctrl / Cmd + M : Minify JSON to single line
  • Esc : Clear editor / close modals

📚 JSON Syntax, Schema, and Debugging

JSON objects use double-quoted keys, colon-separated values, and comma-separated members. JSON arrays use square brackets. Trailing commas, comments, single-quoted strings, and unquoted keys are common errors because they belong to JavaScript-like syntax, not standard JSON under RFC 8259.

Valid JSON

{
  "user": {
    "id": 42,
    "active": true
  }
}

Common mistakes

{
  user: 'Ada',
  active: true,
}

Syntax validation answers “can a parser read this?” Schema validation answers “does this data have the required shape?” Use JSON Schema or application tests for required fields, types, ranges, and formats after the syntax is valid. For debugging, start with the first reported line and column, check the character immediately before it, then format the corrected document to reveal its structure.

JavaScript

const pretty = JSON.stringify(
  JSON.parse(rawJson), null, 2
);

Python

pretty = json.dumps(
    json.loads(raw_json), indent=2
)

❓ Frequently Asked Questions (FAQ)

How do I validate and format JSON online?
Simply paste your raw JSON string into the editor above and press Ctrl+Enter (or click Validate & Format). JSONLints will check your syntax instantly and format the text with clean indentation.
What causes common JSON syntax errors?
The most common JSON errors are trailing commas before closing braces ({ "a": 1, }), unquoted keys ({ a: 1 }), using single quotes instead of double quotes, and including JavaScript or Python comments.
How is JSONLints different from classic jsonlint.com?
JSONLints (jsonlints.com) is the next-generation JSON studio. Unlike legacy validation tools, JSONLints includes one-click Auto-Repair for broken syntax (single quotes, trailing commas, missing quotes), interactive Tree & Table data inspectors, visual side-by-side Diff comparator, and instant code generation for TypeScript, Python, and Go.

📖 JSON Developer Guides & Tutorials

Explore in-depth technical guides written by engineers for debugging, formatting, and converting JSON:

🛠️ How to Fix Common JSON Errors →

Solve unexpected tokens, unquoted keys, trailing commas, and single quotes.

⚡ JSON to TypeScript, Python & Go →

Generate strongly-typed interfaces, dataclasses, and Go struct tags.

🔄 Compare JSON Files Side-by-Side →

Semantic side-by-side visual diff for payloads and API responses.

⚖️ JSON vs YAML Comparison →

When to use JSON vs YAML for APIs, Kubernetes, and configs.

💻 Format JSON in JS & Python →

Pretty-print payloads using JSON.stringify and json.dumps.

⚡ How to Minify JSON Safely →

Strip whitespace without mutating property values.