JSON Formatter & Converter
Format, validate, minify JSON — convert to TypeScript types and Go structs. Free, no signup, no server calls.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is the most widely used format for API responses, configuration files, and data storage in modern web applications.
How to Format JSON
Formatting JSON (also called "beautifying") means adding proper indentation and line breaks to make it human-readable. Paste your JSON into the editor above and click "Format" — the tool will automatically validate and beautify with 2-space indentation. You can also choose 4-space indentation or sort keys alphabetically.
JSON Validator
A JSON validator checks whether your data is syntactically correct. Invalid JSON will cause errors in applications and APIs. This tool validates JSON in real-time as you paste, showing exactly where syntax errors occur — missing commas, unmatched quotes, or trailing commas.
JSON to TypeScript Converter
Generate TypeScript interfaces from any JSON object or array instantly. Paste your JSON and click "Generate TypeScript" to get properly typed interfaces with string, number, boolean, and nested types inferred from the data. Supports deeply nested objects and arrays — each unique object shape gets its own exported interface.
JSON to Go Struct Converter
Convert any JSON to properly typed Go structs with JSON tags. The tool generates idiomatic Go code with PascalCase field names, correct types (string, int, float64, bool), and json:"fieldName" struct tags for serialization.
Frequently Asked Questions
Is this JSON formatter free?
Yes, completely free. No signup, no usage limits, no API calls. Everything runs in your browser.
Does this tool send my data to a server?
No. All JSON formatting, validation, conversion, and tree viewing happens 100% client-side in your browser using JavaScript. Your data never leaves your machine.
What is JSON to TypeScript conversion?
It automatically generates TypeScript interface declarations from your JSON data. This is useful when you receive JSON from an API and want type-safe access in your TypeScript project.
What is JSON to Go struct conversion?
It generates Go struct types from JSON, complete with json tags. This eliminates the tedious manual work of writing Go types to match JSON API responses.
Can I minify JSON for production?
Yes. The Minify tab removes all whitespace from your JSON, producing the smallest possible string. This is useful for reducing payload sizes in production APIs and storage.
What is a JSON tree viewer?
A tree viewer displays JSON as a collapsible hierarchy, making it easier to explore deeply nested structures. Click the ▼ arrows next to objects and arrays to expand or collapse sections.