Can I convert JSON5 to standard JSON?

Yes, JSON5 parsers output standard JavaScript objects that can be serialized to JSON. Comments and formatting are lost, but data is preserved.

Should I use JSON5 for APIs?

No, use standard JSON for APIs. JSON5 is for human-edited files. APIs should use strict, widely-supported JSON format.

Do browsers support JSON5?

Not natively. JSON5 requires a parser library. Only use JSON5 where you control the parsing environment (Node.js configs, build tools).

JSON5 Validator

Guide & TutorialOffline

Validate and format JSON5 data with extended syntax support

Validate and format JSON5 data with extended syntax support instantly with our free online JSON5 validator. This tool helps developers working with JSON5 verify extended JSON syntax including comments, trailing commas, and unquoted keys. Simply paste your JSON5 data and get instant validation.

Note

JSON5 extends JSON syntax to include comments, trailing commas, unquoted keys, and more. If the json5 package is not installed, this tool will fall back to standard JSON validation.

Input JSON5

0 characters, 1 lines

Validation Result

About JSON5

JSON5 is a superset of JSON with a more human-friendly syntax. It supports features like:

Single and multi-line comments
Trailing commas in objects and arrays
Unquoted object keys
Single-quoted strings
Hexadecimal numbers
Leading and trailing decimal points

About JSON5 Validator

JSON5 validation checks extended JSON syntax that allows comments, trailing commas, unquoted keys, and other developer-friendly features. JSON5 is ideal for configuration files where human readability matters more than strict JSON compatibility.

How It Works

The validator parses JSON5 syntax, which extends JSON with: single and multi-line comments, trailing commas, unquoted object keys, single-quoted strings, hexadecimal numbers, and more. It reports errors while accepting valid JSON5 features.

Technical Details

JSON5 adds: // and /* */ comments, trailing commas in arrays/objects, unquoted keys (if valid identifiers), single-quoted strings, multi-line strings, hex numbers (0xFF), Infinity/-Infinity/NaN, and leading/trailing decimal points (.5, 5.).

Common Use Cases

Configuration Files

Config files with comments for documentation.

VS Code settings use JSONC (similar to JSON5)

Development Settings

Babel, ESLint configs with comments.

Documentation Examples

JSON examples with explanatory comments.

Human-Edited Data

Data files that developers frequently edit.

Code Examples

JSON5 Features

javascript

{
  // Single-line comment
  name: 'John',          // Unquoted key, single-quoted value
  age: 30,               // Trailing comma OK
  /* Multi-line
     comment */
  hex: 0xFF,             // Hexadecimal
  infinity: Infinity,    // Special numbers
  'quoted-key': true,    // Quoted keys for special chars
}

JSON5 allows comments, trailing commas, unquoted keys, and other features not allowed in standard JSON.

Tips & Best Practices

Use JSON5 for config files that need comments
Convert to standard JSON for data exchange
Use a JSON5 parser library for your platform
Consider JSONC if you only need comments
Document that files use JSON5, not standard JSON

Common Mistakes to Avoid

Assuming all JSON parsers support JSON5
Using JSON5 for API responses
Forgetting JSON5 requires special parser
Mixing JSON5 with tools expecting standard JSON

When to Use This Tool

Use JSON5 validation for configuration files, build tool settings, and any human-edited JSON that benefits from comments and relaxed syntax. Not for API data exchange.

Frequently Asked Questions

JSON5 allows more features (unquoted keys, trailing commas, single quotes). JSONC (JSON with Comments) only adds comments to standard JSON. VS Code uses JSONC. Choose based on what your parser supports.

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{ // Single-line comment name: 'John', // Unquoted key, single-quoted value age: 30, // Trailing comma OK /* Multi-line comment */ hex: 0xFF, // Hexadecimal infinity: Infinity, // Special numbers 'quoted-key': true, // Quoted keys for special chars }