Fix my messy JSON
Format, validate, and beautify JSON with syntax highlighting
Formatted JSON will appear here
How to Format JSON Instantly
Transform messy JSON into clean, readable code in seconds. DevSensei's JSON Formatter helps developers debug APIs, validate data structures, and beautify configuration files.
Paste Your JSON
Copy your JSON data from any source - API responses, config files, or database exports - and paste it into the input area.
Choose Your Format
Select beautify for readable output with proper indentation, or minify for production-ready compressed JSON.
Copy & Use
Your formatted JSON is ready! Copy it to clipboard with one click or download as a file.
Why Use DevSensei?
What makes DevSensei different from other tools
100% Privacy
Your JSON never leaves your browser. All processing happens locally on your device.
Smart Error Detection
Get helpful, mentoring-style error messages that explain exactly what's wrong and how to fix it.
Syntax Highlighting
Color-coded output makes it easy to distinguish keys, values, strings, and numbers at a glance.
Frequently Asked Questions
Common questions about this tool
Absolutely! DevSensei processes everything locally in your browser. Your data never touches our servers, making it safe for sensitive information like API keys or personal data.
DevSensei can handle JSON files up to several megabytes. For extremely large files, we recommend using our chunked processing mode for optimal performance.