Free JSON Minifier – Compress JSON Online

Minify JSON by removing whitespace and formatting. See size reduction percentage. Validate JSON syntax. Copy or download result. 100% free, browser-based.

What Is JSON Minification?

JSON minification is the process of removing all unnecessary characters from JSON data without changing its functionality. This includes:

Whitespace between tokens
Line breaks (newlines)
Indentation (tabs/spaces)
Comments (if present in non-standard JSON)

The result is valid JSON that's smaller in size but harder for humans to read.

How to Use This Tool

Step 1: Paste JSON

Enter or paste your formatted JSON into the input area.

Step 2: View Results

See the minified output instantly with size comparison.

Step 3: Copy or Download

Copy to clipboard or download as a .json file.

Why Minify JSON?

Reduce File Size

Minified JSON is typically 30-70% smaller than formatted JSON. For large datasets, this can mean megabytes of savings.

Example:

// Formatted (89 characters)
{
  "name": "John",
  "age": 30,
  "city": "New York"
}

// Minified (42 characters - 53% smaller)
{"name":"John","age":30,"city":"New York"}

Faster Network Transfer

Smaller payloads mean faster API responses and reduced latency for users.

Lower Bandwidth Costs

For applications serving millions of requests, minification can significantly reduce data transfer costs.

Improved Load Times

Web applications loading JSON data will render faster with minified payloads.

Size Reduction Examples

Content Type	Formatted	Minified	Savings
Simple object	150 bytes	80 bytes	47%
Array of 10 items	2 KB	1.2 KB	40%
Complex nested JSON	50 KB	25 KB	50%
API response	500 KB	250 KB	50%

When to Minify JSON

DO Minify:

Production API responses
Configuration files in bundles
JSON stored in databases
Data sent over networks

DON'T Minify:

Development/debug logs
Human-readable config files
Version-controlled JSON files
Documentation examples

JSON Validation

This tool validates your JSON before minifying. Common errors detected:

Missing quotes around keys
Trailing commas
Single quotes (must be double quotes)
Unescaped special characters
Invalid Unicode sequences

Technical Details

How It Works

Parse JSON using native JSON.parse()
Re-serialize using JSON.stringify() without spacing
Calculate size reduction percentage

Browser-Based Processing

All processing happens in your browser using JavaScript. Your data never leaves your device.

Frequently Asked Questions

Does minification change my data?

No. The JSON structure and values remain identical. Only formatting is removed.

Can I minify invalid JSON?

No. The tool first validates the JSON. Invalid JSON will show an error.

What's the maximum file size?

There's no hard limit, but very large files (10MB+) may slow down your browser.

Is my data secure?

Yes. All processing is client-side. Nothing is sent to any server.

JSON Minifier