100% Browser-Based • No Upload • Free
Free JSON Formatter Format, Validate & Fix
Paste messy JSON and get beautifully formatted output instantly. Validates syntax, highlights errors, and even handles Python dict syntax. No data leaves your browser.
No sign-up required to try
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No files uploaded
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Free forever
How It Works
1
Select or drop your file
2
Processed in your browser — nothing uploaded
3
Download the result — done!
Key Features
Why Use UniTrack JSON Formatter
The developer's best friend for messy JSON — format, fix, and validate in seconds.
Auto-Fix & Validate
Detects and highlights JSON syntax errors. Fixes common issues like trailing commas and single quotes automatically.
Python Dict Support
Paste Python dictionaries and they'll be converted to valid JSON. Handles True/False/None to true/false/null conversion.
Minify & Beautify
Pretty-print with custom indentation or minify to a single line. Copy formatted output with one click.
FAQ
Frequently Asked Questions
Yes! Common issues like trailing commas, single quotes instead of double quotes, and unquoted keys are automatically detected and fixed. Syntax error locations are highlighted for manual fixes.
Absolutely. All processing happens in your browser using JavaScript. No data is sent to any server — your API keys, config files, and sensitive data stay completely private.
Yes! Paste a Python dict output and it will be automatically converted to valid JSON. True→true, False→false, None→null, and single quotes→double quotes are all handled.
Format Your JSON for Free
Beautify, validate, and fix JSON instantly — no upload, no signup, no limits.
No sign-up required
100% browser-based
Free forever