JSON Formatter
Format, validate and beautify JSON with configurable indentation.
A JSON formatter takes minified or messy JSON and reformats it with clean indentation so it is easy to read. It also validates your input and shows meaningful errors when the JSON is invalid.
How to Use the JSON Formatter
- Paste your JSON. Enter minified or messy JSON.
- Choose indentation. Pick 1–8 spaces for the output indent.
- Copy the result. Copy the formatted JSON or download it as a file.
This tool processes your input locally in your browser. Nothing is uploaded.
What Is JSON Formatter?
JSON (JavaScript Object Notation) is the most common data format for APIs and configuration. A JSON formatter makes it readable by adding indentation and validating correctness.
What is a JSON formatter?
It parses your JSON and re-prints it with consistent indentation, line breaks and spacing. If the JSON is invalid, it reports the error with context so you can fix it quickly.
What makes JSON valid?
Valid JSON uses double quotes for keys and strings, proper commas, and correct brackets. Objects use braces {}, arrays use brackets [], and numbers, booleans, null and strings are the valid value types. Trailing commas and single quotes are not allowed.
Common JSON errors
The most common mistakes are missing commas between properties, trailing commas, single quotes instead of double quotes, and unmatched braces. This formatter points to the approximate line of the error.
Why format JSON?
Formatted JSON is far easier to read, debug and share. Minified JSON saves space for transport, but formatted JSON is essential for working with data by hand.
Key Features
- Beautifies JSON with indentation
- Validates input
- Shows line-based errors
- Copy and download output
Examples
- Minified: {"a":1,"b":[1,2,3]} becomes pretty-printed with each key on its own line.
- API responses and config files are typical inputs.
Common Use Cases
- Debugging API responses
- Reading config files
- Preparing JSON for sharing
Tips & Best Practices
- Use 2-space indentation as the common default.
- Minify before sending JSON to save bandwidth.
Limitations
- Very large JSON may be slow to render; keep inputs reasonable.