What is the difference between JSON formatting and JSON validation?

Formatting (or prettifying) adds indentation and line breaks to make your JSON human-readable. Validation checks whether your JSON is syntactically correct — whether it can be parsed without errors by any JSON parser. Our tool does both: it validates as you type and formats or minifies on demand.

Is it safe to paste my API keys or tokens into this tool?

Yes. The JSON formatter runs 100% in your browser. Your JSON is never sent to our servers — it is parsed and formatted entirely using JavaScript's native JSON.parse() and JSON.stringify() methods. Your API keys, passwords, tokens, or sensitive configuration data never leave your device.

What causes 'Invalid JSON' errors?

Common JSON syntax errors include: missing or extra commas, unquoted object keys (e.g. {name: 'John'} instead of {"name": "John"}), single-quoted strings instead of double-quoted, trailing commas after the last array element or object property, and undefined or NaN values which are not valid in JSON.

What is minified JSON used for?

Minified JSON removes all whitespace and line breaks to produce the smallest possible JSON string. It is used in production environments where file size matters: API responses, localStorage entries, HTML data attributes, or JSON embedded in JavaScript. Minified JSON is valid JSON — just harder for humans to read.

Free JSON Formatter & Validator Online — Prettify & Minify JSON

Free JSON Formatter, Validator & Minifier — Online Tool

The TextDiffy JSON formatter lets you instantly beautify, validate, and minify any JSON string. Whether you're a developer debugging an API response, a data analyst cleaning up a dataset, or a student learning JSON syntax — this tool gives you instant, readable output with no setup required.

Format (Prettify) JSON

Click Format / Prettify to convert a compact or minified JSON string into a properly indented, human-readable format. Choose between 2 spaces, 4 spaces, or tab indentation depending on your project's coding standards.

Validate JSON Instantly

The tool validates your JSON as you type. A green banner appears when the JSON is valid. If there's a syntax error, a red banner shows the exact parser error message — including the position — so you can fix it immediately.

Minify JSON

Click Minify to compress your JSON by removing all whitespace and line breaks. Useful for reducing payload size in API requests, localStorage entries, production config files, or HTML data attributes.

Common Use Cases

API debugging: Paste raw API responses and format them for easy reading.
Config files: Beautify package.json, tsconfig.json, or any JSON config.
Data inspection: Format MongoDB exports, REST API payloads, or NoSQL results.
Minification: Compress JSON before embedding in HTML or sending in a POST request.
Syntax validation: Catch missing commas, unquoted keys, or trailing commas before running your code.

Privacy & Security

Your JSON is never sent to any server. All formatting, validation, and minification happens entirely in your browser using JavaScript's built-in JSON.parse() and JSON.stringify(). Your API keys, tokens, database exports and config data remain 100% private on your device.