TidyFigure

JSON Formatter & Validator

  • 100% free
  • No sign-up
  • Runs in your browser

Paste JSON to check it and format it with readable indentation. If it's invalid, you'll see the line and column of the error and a hint for the usual culprits: single quotes, unquoted keys and trailing commas. "Minify" removes all whitespace for the smallest possible size. Your data never leaves your browser.

Everything runs in your browser. Nothing you type is sent anywhere.

What is JSON?

JSON (JavaScript Object Notation) is the most common format for sending data between apps, websites and APIs. It's plain text made of two structures: objects (key–value pairs in curly braces) and arrays (ordered lists in square brackets). Values can be strings, numbers, true, false, null, or more objects and arrays.

{ "name": "TidyFigure", "tools": 40, "free": true, "categories": ["image", "pdf", "text"], "owner": null }

The most common JSON errors

  • Single quotes: JSON strings and keys must use double quotes. {'a': 1} is invalid; {"a": 1} is valid.
  • Unquoted keys: {name: "x"} works in JavaScript but not in JSON.
  • Trailing commas: [1, 2, 3,] has an extra comma before the bracket.
  • Comments: JSON doesn't allow // or /* */ comments.
  • Special values: undefined, NaN and Infinity aren't valid JSON. Use null.
  • Unescaped characters: quotes and backslashes inside strings must be escaped as \" and \\, and line breaks as \n.

Format versus minify

Formatting (also called beautifying or pretty-printing) adds line breaks and indentation so people can read the structure. Two spaces is the most common style; four spaces and tabs are popular in some teams. Minifying removes every unnecessary space and line break. It doesn't change the data, but it makes files smaller for storage and network transfer.

Sorting keys

JSON objects have no meaningful key order, so sorting keys alphabetically doesn't change the data. It's helpful for comparing two JSON files, reviewing config changes, or finding a key quickly in a large object. Arrays are never reordered, because their order does matter.

Private by design

API responses and config files often contain tokens, emails and other sensitive data. This formatter uses your browser's built-in JSON parser and never sends your data to a server, so it's safe to paste production data.

Frequently asked questions

How do I format JSON?

Paste it into the box. It is checked and pretty-printed with indentation automatically. Copy or download the result.

How do I find the error in my JSON?

If the JSON is invalid, the tool shows the error message, the line and column, the text around the problem, and a tip for common mistakes.

Why is my JSON invalid with single quotes?

The JSON standard only allows double quotes for strings and keys. Replace single quotes with double quotes.

Does minifying JSON change the data?

No. It only removes whitespace. The values and structure are identical.

Is it safe to paste sensitive JSON here?

Yes. Parsing and formatting happen in your browser and nothing is uploaded.

Last updated October 2026 · More developer tools