JSON Formatter & Validator Online Free
JSON Formatter & Validator is an online tool that formats, validates, and minifies JSON data directly in your browser. It works by parsing your input with the native JavaScript JSON engine and re-serialising it with your chosen indentation. Users can beautify messy JSON, compress it to a single line, or check whether a string is valid JSON — all without uploading anything to a server.
Frequently Asked Questions
What is a JSON formatter?
A JSON formatter takes raw or minified JSON text and restructures it with consistent indentation and line breaks, making it easy for humans to read and debug. It also validates the JSON syntax and reports any errors.
Is my JSON data sent to a server?
No. Privatool processes all JSON entirely in your browser using the native JavaScript JSON.parse() and JSON.stringify() APIs. Your data never leaves your device and is never sent to any server.
What is the difference between Format and Minify?
Format (Beautify) adds indentation and line breaks to make JSON human-readable. Minify removes all unnecessary whitespace to produce the smallest possible JSON string, which is useful for reducing payload size in APIs and network requests.
How do I find the error in my invalid JSON?
When validation fails, Privatool displays the error message from the browser's JSON parser, including the line number and column where the error was detected. Common mistakes include trailing commas, missing quotes around keys, and mismatched brackets.
What JSON syntax is supported?
This tool supports standard JSON as defined by RFC 8259 — the same spec used by all major programming languages. JSON5, JSONC (with comments), and other extended formats are not supported, as they are not valid standard JSON.
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