JSON Formatter & Beautifier
Paste or type JSON and instantly format it with proper indentation. Validates structure, highlights errors, and supports minification. All processing is done in your browser — no data is sent to any server.
Try an example:
Why use a JSON Formatter & Prettifier?
Minified JSON is compact but unreadable. A formatter instantly adds indentation and line breaks so you can scan structure, spot typos, and debug API payloads in seconds. Whether you're working with config files, REST responses, or database exports, prettified JSON reduces errors and speeds up review. Use it alongside the JSON validator and JSON diff tool for a complete developer workflow.
Consistent indentation
Choose 2 spaces, 4 spaces, or tabs to match your project style guide — and re-format in one click.
Inline validation
Syntax errors are caught immediately as you type, so you never paste broken JSON into production.
Minify mode
Strip all whitespace for compact storage or transmission without manually editing the JSON.
Common JSON formatting errors & fixes
These mistakes account for the vast majority of JSON parse errors seen in practice.
| Error | Example (broken) | Fix |
|---|---|---|
| Trailing comma | {"a":1, "b":2,} | Remove the last comma before } or ] |
| Single quotes | {'key': 'value'} | JSON requires double quotes for keys and strings |
| Unquoted keys | {name: "Alice"} | Wrap all keys in double quotes: "name" |
| Comments | {"a":1 // comment} | JSON does not support comments — remove them |
| Undefined / NaN | {"val": undefined} | Use null instead of undefined, NaN, or Infinity |