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JSON Formatter & Validator

Format and pretty-print JSON instantly, minify it for production, or validate it and get error messages with exact line numbers.

Pretty-print Minify Validate Error line numbers Syntax highlight Copy output
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Free · No credit card · 50 credits/day

What the formatter does

✨

Pretty-print

Adds consistent 2-space indentation and line breaks. Nested objects and arrays are indented to make structure immediately readable.

🗜️

Minify

Removes all non-essential whitespace to produce the smallest valid JSON. Use before shipping to production APIs or CDNs.

✅

Validate

Checks compliance with RFC 8259 — balanced brackets, quoted keys, no trailing commas, valid value types.

🎯

Error line numbers

When JSON is invalid, shows the exact line and column where the parser failed — no more hunting through large payloads.

🎨

Syntax highlighting

Keys, strings, numbers, booleans and null are colour-coded for fast visual scanning of complex nested structures.

📋

One-click copy

Copy the formatted or minified output to clipboard instantly — no manual text selection needed.

Frequently asked questions

What is the difference between JSON formatting and validation?

Formatting adds indentation and line breaks to make JSON human-readable. Validation checks whether the JSON is syntactically correct — all keys are quoted, brackets are balanced, no trailing commas. You can have well-formatted JSON that is still invalid (e.g. JavaScript-style comments are not allowed in JSON).

Why does JSON not allow trailing commas?

The JSON spec (RFC 8259) was designed for strict interoperability across all languages. Trailing commas are legal in JavaScript object literals but excluded from JSON to keep parsing simple. If you need trailing commas, use JSON5 or JSONC (JSON with Comments), which are supersets supported by many modern tools.

What is the difference between JSON and XML?

JSON uses key-value pairs and arrays with a compact, JavaScript-derived syntax. XML uses opening/closing tags, making it more verbose but better for document-centric data. JSON is typically preferred for APIs and configuration; XML for document exchange, SOAP services, and formats like SVG and RSS.

Is minified JSON valid JSON?

Yes. Whitespace between tokens is optional in JSON. Minifying removes this whitespace to reduce file size, but the result is 100% valid JSON. Minification is commonly used to reduce payload size in API responses and files shipped to browsers.

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Format your JSON in seconds

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