JSON Formatter & Validator: The Privacy-First Tool

Our JSON Formatter is a free, offline-capable browser tool that formats JSON and converts CSV/Excel to JSON without uploading data to any server. Designed for modern developers, it processes everything locally on your device.

100% Client-Side Processing

Your data never leaves your browser. Unlike other JSON formatters that upload your sensitive payloads to remote servers, our tool runs entirely locally. We use modern web technologies to parse and beautify your JSON directly in your memory.

Works Offline Without WiFi

Install the JSON Formatter as a Progressive Web App (PWA) and use it anywhere. Whether you're on a plane or experiencing network outages, your favorite JSON tool is always available with zero latency.

Core Features

Format & Beautify JSON: Paste minified or messy JSON to instantly prettify it with proper indentation.
Validate JSON Syntax: Get real-time syntax checking with precise line numbers to help you find that missing comma or bracket.
Minify JSON: Compress your JSON payloads to save bandwidth before sending them over the wire.
CSV to JSON Converter: Transform tabular data (CSV/Excel) into JSON arrays in seconds.
Code Generator: Automatically generate Go structs, TypeScript interfaces, Java classes, and more from your JSON objects.

Common Use Cases

Debugging API Responses

When building or consuming REST APIs, you often receive large, unformatted JSON blobs. Paste them into our JSON Formatter to instantly visualize the structure, inspect data types, and find specific fields using our Wildcard Search feature.

Generating Types and Models

Stop writing boilerplate code by hand. Paste your JSON payload, switch to the Code Gen tool, and instantly get strongly-typed structs or interfaces for 11 different programming languages, saving you hours of manual typing.