JSON Formatter / Validator
Format /jsonFree JSON formatter and validator with native parsing, local processing, and an error marker on the exact line.
Strict JSON only. Drop a .json file or paste from the clipboard.
Formatted or minified JSON will appear here.
Paste JSON. Output updates as you type. 5 lines 56 B local only
How it works
Free JSON formatter, validator, and minifier with clear local parse feedback.
Use it to inspect API responses, configuration objects, and copied JSON payloads.
Example
Format {"local":true} into an indented object, or validate it without producing output.
Notes
- Output follows the selected mode as you type; Validate only confirms syntax.
- A parse error marks the offending line in the gutter and the position in the text.
- Comments and JSON5 syntax are intentionally out of scope.
Constraints
- Strict JSON only; comments and JSON5 syntax are not accepted.
- Limit: 3 MiB input. Nothing is uploaded or silently truncated.
Common errors
- Trailing commas
- Unquoted keys
- Comments or incomplete values
When to use it
Use it to inspect API responses, configuration objects, and copied JSON payloads.
Formats: Strict JSON text, UTF-8 strings.