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.

Format JSON Free All Tools
No sign-up required to try • No files uploaded • 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.

Your Data Never Leaves Your Browser

Unlike other online tools, we don't upload your files to our servers. Everything is processed using JavaScript directly in your browser. When you close the tab, your data is gone. Zero tracking, zero risk.

0
Server uploads
0
Data stored
0
Tracking
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.

Format JSON Now Browse All Tools
No sign-up required 100% browser-based Free forever