JSON Formatter — Free Online JSON Validator & Beautifier
Format, validate, and minify JSON instantly in your browser. Your data never leaves your device — no account needed.
Paste JSON to format it
Formatted, validated output appears here — or load a sample to see how it works.
About the JSON Formatter
JSON (JavaScript Object Notation) is the universal data format used by APIs, config files, and databases. Raw JSON from an API is often minified — stripped of spaces and line breaks to reduce payload size — making it nearly impossible to read. This tool formats and validates JSON instantly in your browser.
Format vs. minify
Format → Adds indentation (2 spaces) and newlines for human readability
Minify → Removes all whitespace to reduce file size for production use
Validate → Syntax errors are caught and shown with the exact problem
Common JSON errors
- ❌Trailing commas after the last property or array item (valid in JS, not in JSON)
- ❌Single quotes instead of double quotes around keys or string values
- ❌Unescaped special characters inside strings (newlines, tabs, backslashes)
- ❌Comments — JSON does not support // or /* */ comments, unlike JavaScript
Related: Case Converter to normalize JSON key naming (camelCase vs snake_case), or DB to CSV to export SQLite data for processing.
Frequently Asked Questions
Is the JSON Formatter free?
Yes — completely free. No account and no data sent to a server.
Does this JSON formatter send my data anywhere?
No. Formatting and validation happen entirely in your browser. Your JSON never leaves your device.
Do I need an account?
No account, no login, and no signup required.
Can it format invalid JSON?
No — but it will highlight the exact line and position of the syntax error so you can fix it.
What is the difference between format and minify?
Format adds indentation and line breaks for readability. Minify removes all whitespace to reduce file size for production use.
Is there a size limit on the JSON I can paste?
No hard limit. Very large files (10MB+) may be slow in the browser.