What Is This Tool?
The JSON Formatter & Validator checks whether JSON is valid and formats it with indentation or minifies it into one line.
What Can You Do With It?
Make API responses readable. Find syntax errors in configuration files. Minify JSON to save space.
How Does It Work?
The browser’s built-in JSON parser reads your text. If it is valid, it is written back out with indentation (format) or without spaces (minify). If not, the parser’s error message is shown.
Key Benefits
Uses the same strict parser as JavaScript. Instant feedback.
Limitations and Important Notes
Comments and trailing commas are not valid JSON and will be rejected. Very large files may be slow in the browser.
Privacy and Security
This tool runs entirely in your web browser. Your input and results are processed on your device and are not uploaded to Usekit servers.
Real-World Example
Input {"name":"Usekit","tools":54} → Format gives the same data on separate indented lines. Input {"a":1,} shows a syntax error.
Frequently Asked Questions
Why is my JSON invalid?
Common causes are single quotes, trailing commas, missing quotes around keys, or comments.
Is my data uploaded?
No, parsing happens in your browser.
What does minify do?
It removes spaces and line breaks without changing the data.
Related Tools
How to use this tool
- Paste your JSON.
- Click Format to validate and indent, or Minify to compress.
- Copy the result or fix the error shown.