Format, validate and minify JSON instantly. Paste messy JSON and get it clean.
Turn a wall of minified JSON into something readable, or do the reverse. Validation errors highlight exactly where to look.
The five most common causes: missing comma between key-value pairs, trailing comma after the last item, single quotes instead of double, unquoted keys, and comments. Strict JSON forbids all five.
Yes — arbitrary nesting depth. The formatter indents each level so structure is visible. Very deep nesting (5+ levels) usually indicates the data should be flattened, however.
Yes. The formatter runs entirely in your browser. Nothing is sent to a server, logged, or stored. Safe for payloads containing tokens, keys, or personal data.
Browsers comfortably handle JSON up to about 10–20 MB. For multi-gigabyte files, use a command-line tool like jq.
Yes — click the Minify button to remove all whitespace and produce a single-line, compact version suitable for storage or transmission.
JSON is the lingua franca of modern APIs, but minified or deeply nested JSON is effectively unreadable. The ConvertDox JSON Formatter solves three problems at once: it indents the structure so you can see what nests inside what, it validates the input and points at the exact line where syntax breaks, and it lets you minify cleanly when you need a one-line version for a database column or environment variable. Crucially, the whole operation happens in your browser. That matters because real-world JSON often contains auth tokens, API keys, personally identifiable information, or trade secrets — exactly the kind of data you should never paste into an online tool that calls a server. ConvertDox doesn't make a network request when you click Format; the parser is the browser's own JavaScript engine. You can verify this yourself by opening DevTools, switching to the Network tab, and clicking Format — nothing fires. Beyond formatting, the tool surfaces useful structural stats — counts of keys, strings, numbers, arrays, and objects — which is the fastest way to spot whether an API response matches your expectations. It also handles edge cases that trip lesser tools: deeply nested structures, very large numbers, escaped characters, and Unicode strings. If you regularly look at API responses, save this page as a tab — formatting becomes a one-click reflex.
A JSON formatter takes raw, messy JSON data and reformats it into a clean, readable, properly indented structure. JSON (JavaScript Object Notation) is the standard format for exchanging data between web servers, APIs, and applications, but it often arrives minified or on a single line, making it impossible to read. A formatter adds proper indentation and line breaks, and a validator checks that the JSON is correctly structured, flagging errors like missing commas or brackets.
Developers work with JSON constantly — reading API responses, editing config files, debugging data. When JSON is minified into one long line, finding a specific value or spotting a syntax error is painful. The ConvertDox JSON Formatter beautifies your JSON for readability, validates it to catch errors, and can minify it back down when you need a compact version for production. Everything runs in your browser, so your data never leaves your device — important when working with sensitive API keys or private data.
Paste a raw API response to see it cleanly formatted, making it easy to find the fields and values you need.
Check that a JSON file or snippet is syntactically correct before using it, catching errors early.
Format config files like package.json or settings files so they're readable and easy to edit by hand.
Compress formatted JSON into a compact single line to reduce payload size in production.
Format JSON examples cleanly before adding them to API docs or technical guides.
See nested objects and arrays laid out clearly to understand how a piece of JSON is structured.
Yes, completely free with no signup and no limits on how often you use it.
Yes. Formatting happens entirely in your browser — your JSON is never uploaded to or stored on any server, so it's safe to format sensitive data.
Format (beautify) adds indentation and line breaks for readability. Minify removes all unnecessary whitespace to create the smallest possible single-line version.
The validator detected a syntax error — commonly a trailing comma, a missing quote, an unquoted key, or an unmatched bracket. Fix the flagged issue and format again.
Yes, it handles large JSON, though extremely large inputs may take a moment to process in the browser.
For converting JSON to CSV, use our JSON to CSV tool. This tool focuses on formatting, validating, and minifying JSON.