What this tool does
The JSON formatter takes raw, minified or messy JSON and reformats it with clean indentation so it's easy to read. It also validates the JSON and reports the exact error if the syntax is invalid.
Why format JSON?
APIs often return JSON on a single line to save bandwidth. That's efficient for machines but hard for humans to debug. Formatting (or "pretty-printing") reveals the structure — objects, arrays and nesting — so you can spot problems quickly.
How it works
The tool parses your text with the browser's JSON engine and re-serialises it with two-space indentation. If parsing fails, it surfaces the error message so you can find the misplaced comma, bracket or quote.
How to use it
- Paste your JSON.
- Click format to beautify and validate it.
- Copy the clean output.
Common JSON mistakes it catches
- Trailing commas after the last item
- Single quotes instead of double quotes
- Missing brackets or braces
- Unquoted keys
Your data is parsed entirely in your browser and never uploaded.