JSON Validator

Free JSON Validator — Validate & Pretty-Print JSON

Welcome to the UtilixVerse JSON validator. Validate your JSON syntax instantly — paste raw JSON or drop a file, and the tool parses it, highlights any errors with exact line and column numbers, and pretty-prints valid JSON with syntax-coloured indentation. Essential for debugging API responses, configuration files, and data imports.

How It Works

The tool uses JavaScript's native JSON.parse() to validate your input. If parsing fails, the error message includes the exact position (line and column) where the problem occurs. Valid JSON is automatically pretty-printed with 2-space indentation and syntax highlighting, making nested structures easy to read at a glance.

Errors It Detects

Who Uses This Tool?

• → Developers — debug API responses, .env files, package.json, and configuration before deploying
• → Data analysts — validate JSON exports from databases, APIs, or data pipelines before import
• → Students — learn JSON structure, practice syntax, and understand nested data formats
• → API consumers — quickly verify payloads before sending to REST or GraphQL endpoints

Tips for Fast Debugging

1. 1. Check the line and column number in the error message — it points to the exact problem character.
2. 2. The most common error is a trailing comma after the last property or array element.
3. 3. Use the pretty-print output to visually scan for missing commas or mismatched braces.
4. 4. For minified JSON, paste it first — the validator will format it and show any hidden syntax errors.

100% private — all validation runs locally in your browser with no uploads.

Check whether a JSON string is valid before you rely on it in code, an API call, or a config. The validator parses the document the same way JSON.parse does and pinpoints the first error with its position.