JSON Lint

Use this JSON lint online tool to validate JSON as you type and format JSON with consistent indentation. It is built for API payloads, config files, logs, and data exports.

1. Paste or type JSON into the editor.
2. Review the status banner for the first error and suggestion.
3. Use "Jump to error" to move the cursor to the problem line.

1. Pick an indentation size that matches your project.
2. Click "Format JSON" to apply JSON format.
3. Copy the formatted JSON back into your project.

The JSON validator runs in your browser and parses each change as you type. The status banner updates with line and column details, and your input never leaves your device.

• Valid JSON syntax and structure.
• Proper use of quotes, commas, and brackets.
• Common formatting mistakes like trailing commas.

• Catch syntax errors before committing config files.
• Standardize formatting across teams and services.
• Debug API payloads faster with line numbers.
• Share clean JSON for documentation or review.

• Trailing commas after the last item in objects or arrays.
• Unquoted keys or string values.
• Missing commas between properties.
• Using single quotes instead of double quotes.

• Fix the first error shown first; later errors often cascade from one mistake.
• Format the JSON to line up braces, arrays, and nested objects.
• Look for trailing commas and missing commas between properties.
• Confirm keys and string values use double quotes.
• Verify numbers, booleans, and null values are not quoted.

For API payloads and configuration files, validate after each small change to isolate the exact line that broke JSON syntax.