JSON
JSON Formatter
Paste JSON, choose indentation, and format it locally with helpful parse errors and downloadable output.
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Runs locally in your browser. Your input is not uploaded.
How this tool works
Pretty printing makes nested JSON easier to scan, review, and debug.
The formatter waits for the format action, which avoids repeatedly parsing large pasted input while typing.
Examples
- Format an API response with 2-space indentation.
- Download a readable JSON file after pasting minified data.
- Format a nested synthetic API response with four-space indentation, then download the parsed result.
Common use cases
What formatting changes
Formatting parses the JSON and serializes it with readable indentation. It should not change strings, numbers, booleans, nulls, arrays, or object values. It changes whitespace outside strings so the structure is easier to inspect.
Use it after receiving minified API output, copying a log payload, or reviewing a config value that is hard to scan on one line.
When formatting is the wrong first step
- If the input has comments, trailing commas, or unquoted keys, validate and fix syntax first.
- If you need smaller output for transport, use the JSON minifier after confirming the data is valid.
- If the payload contains secrets or customer data, redact it before sharing formatted output.
Invalid or unsafe assumption
Invalid/failure example
{"id":42,} contains a trailing comma and must be rejected as strict JSON.
Mistakes to avoid
- Expecting formatting to repair invalid syntax.
- Pasting JavaScript object literals with comments or single quotes.
- Comparing whitespace instead of parsed values.
Limits of this workflow
Formatting checks syntax but not a business schema.
Very large documents are rejected to protect the browser tab.
Local-processing and privacy boundary
JSON text is parsed in the browser and is not sent to a DevPouch processing endpoint; redact production data before using any web page.
Practical workflow
- Load a synthetic sample or local JSON file.
- Select indentation and format.
- Resolve the first reported syntax position if parsing fails.
- Copy or download only after comparing parsed values.
Related guides
Official references
FAQ
Does formatting change JSON values?
No. Formatting changes whitespace only after the input parses as valid JSON.
Why is my JSON not formatting?
The parser reports syntax errors such as missing commas, unquoted keys, or trailing commas.
Will formatting change JSON values?
No. Successful formatting parses and serializes the same JSON data, although insignificant whitespace changes.