How to use the JSON Formatter
- 1 Paste your JSON into the Input JSON box, for example an API response, a config file or a log entry.
- 2 Choose the indentation you prefer: 2 spaces, 4 spaces or tabs. Tick Sort keys if you want object keys in alphabetical order.
- 3 Press Format / Beautify or use Ctrl+Enter. The formatted result appears on the right.
- 4 If the JSON is invalid, read the message under the boxes. It tells you the line and column where parsing stopped.
- 5 Copy the result or download it as a .json file. Use Minify when you need the smallest possible output for production.
Features
Exact error locations
Instead of a vague invalid JSON message, you get the line and column of the problem, which makes missing commas, trailing commas and unquoted keys quick to fix.
Beautify and minify
Switch between readable, indented output for debugging and compact single-line output for payloads and storage, and see how many bytes you saved.
Sort keys for clean diffs
Sorting object keys alphabetically, including nested objects, makes two JSON documents much easier to compare in code review or a diff tool.
Safe for sensitive data
Parsing and formatting happen in your browser with the standard JSON engine. API keys, tokens and customer records in your JSON are never sent anywhere.
When to use it
Debugging API responses
Responses copied from browser dev tools, Postman or curl often arrive as a single long line. Formatting them reveals the structure so you can find the field you need.
Checking config files before deploying
A single trailing comma in package.json, composer.json or a settings file can break a build. Validate it here first.
Preparing test fixtures
Sort keys and use consistent indentation so fixture files stay tidy and produce small, readable diffs in Git.
Frequently asked questions
What are the most common JSON errors?
Trailing commas after the last item, single quotes instead of double quotes, keys without quotes, and comments. Standard JSON allows none of these, even though JavaScript objects do.
Does the formatter change my data?
Only the whitespace changes. Values, nesting and key order stay the same unless you choose Sort keys. One exception: very large integers beyond JavaScript's safe range (over 9 quadrillion) may lose precision.
Is there a size limit?
There is no fixed limit. Files of several megabytes format in a moment on a modern computer. Very large files depend on your device's memory.
Is my JSON sent to a server?
No. Everything happens in your browser tab, so the tool is safe to use with private or production data.
What is the difference between formatting and validating?
Validating only checks that the JSON is correct. Formatting also rewrites it with line breaks and indentation so it is easy to read.
Reviewed by ToolsUnlocked Team · Last updated