JSON Validator & Formatter
Validate, format, and fix your JSON data instantly. Secure and client-side.
How to Use This JSON Validator
- Paste your JSON: Copy your JSON data into the left input box.
- Instant validation: See real-time validation results on the right. Errors show exact line numbers.
- Format or minify: Click "Prettify" to add indentation, or "Minify" to remove whitespace.
- Copy the result: Click "Copy" to grab the formatted JSON for use in your code.
Common Use Cases for JSON Validation
📝 Kubernetes ConfigMaps & Secrets
Validate JSON data before storing it in ConfigMaps or Secrets. A malformed JSON file can crash your pods on startup.
🔌 API Request/Response Testing
Copy API responses and validate them before writing integration tests. Ensures your API contract is correct.
⚙️ Configuration Files
Many tools use JSON for config (package.json, tsconfig.json). A syntax error can break your entire build.
📦 Data Export/Import
Before importing data into a database, validate the JSON structure to avoid batch errors.
Why JSON Validation Matters
JSON (JavaScript Object Notation) is the de facto standard for data exchange on the web, but it's unforgiving. A single trailing comma, missing quote, or unclosed bracket will break everything.
❌ Common JSON Errors
-
• Trailing commas:
{"key": "value",}(valid in JS, invalid in JSON) -
• Single quotes:
{'key': 'value'}(must use double quotes) - • Comments: JSON does not support comments (use JSONC or strip them before parsing)
-
• Unquoted keys:
{key: "value"}(keys must be strings)
What This Tool Does
✅ Validation
Instantly catch syntax errors with exact error messages. No more cryptic "Unexpected token" messages.
🎨 Prettify (Format)
Auto-indent with 2 spaces. Makes deeply nested JSON readable. Perfect for debugging API responses.
📦 Minify
Remove all whitespace. Reduces payload size by 20-30% for production APIs.
🔒 Privacy First
Runs 100% in your browser. Your data never leaves your device. Safe for sensitive configs.