JSON Minifier

Use this free online JSON minifier to reduce file sizes by removing whitespace, quickly and easily, without installing any software.

Click the UPLOAD FILES button and select the JSON files you wish to minify. Wait for the processing to finish and download files either individually or grouped together.

All processing happens in your browser—no data is uploaded to any server.

What Is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format. It's easy for humans to read and write, and easy for machines to parse and generate. JSON is the dominant format for web APIs, configuration files, and data storage in modern applications. It uses simple key-value pairs, arrays, strings, numbers, booleans, and null values to represent structured data.

Pros of JSON

• Universal compatibility — Supported by virtually every programming language and platform
• Human-readable — Easy to read, write, and debug without special tools
• Simple syntax — Minimal rules make it easy to learn and use
• Lightweight — Less verbose than XML while conveying the same information
• Native JavaScript support — Parse and stringify with built-in browser functions

Cons of JSON

• Verbose formatting — Indentation and line breaks can bloat file size by 50-80%
• No comments — JSON spec doesn't support comments (though some parsers allow them)
• Limited data types — No native support for dates, binary data, or functions
• Repeated keys — No way to avoid duplicate property names in large datasets

Why Minify JSON?

• Remove all unnecessary spaces, tabs, and line breaks
• Reduce file size by 30-80% depending on formatting
• Preserve JSON structure and data integrity

📁 Multiple File Support

• Process multiple JSON files simultaneously
• Batch download or individual file download
• Drag & drop or browse to select files

🔒 Privacy First

• 100% client-side processing - no server uploads
• Files never leave your device
• Safe for sensitive data

📊 Size Comparison

• See original vs minified size for each file
• Percentage reduction displayed
• Preview minified output before downloading

When to Use JSON Minification

API Responses

Reduce bandwidth usage by serving minified JSON from your API endpoints.

Configuration Files

Minimize config files for production deployments while keeping formatted versions for development.

Data Transfer

Reduce network transfer time when sending JSON data between systems.

Storage Optimization

Save disk space when archiving large JSON datasets.

How It Works

1. Select Files - Drag & drop or browse to select .json files
2. Automatic Processing - Files are instantly minified in your browser
3. Review Results - See file size reduction and preview output
4. Download - Get individual files or batch download all

Technical Details

• Processing: Client-side JavaScript (no server required)
• Format: Standard JSON (RFC 8259 compliant)
• Output: Minified JSON with all whitespace removed
• Validation: Parses and validates JSON structure

Difference from GeoJSON/TopoJSON Minifier

This tool only removes whitespace. For geographic data files (GeoJSON/TopoJSON), use the specialized minifiers which also:

• Reduce coordinate precision
• Remove empty properties
• Filter feature properties
• Optimize geometry data

👉 GeoJSON Minifier for geographic data 👉 TopoJSON Minifier for topology data

Tips for Using Minified JSON

• Keep originals — Always maintain formatted copies for development and debugging
• Version control — Commit formatted files to Git, minify during build/deploy
• Testing — Verify functionality after minification (some parsers are strict about trailing commas)
• Compression — Combine minification with gzip/brotli compression for maximum savings (70-90% total)
• Automated builds — Integrate JSON minification into your build pipeline

Related Tools

• GeoJSON Minifier — Specialized optimization for geographic data
• TopoJSON Minifier — Optimize topology-encoded maps
• GeoJSON to SVG — Convert GeoJSON to vector maps
• GeoJSON to PNG — Convert GeoJSON to raster images
• CSV to GeoJSON — Convert CSV data to GeoJSON format