How to use JSON Formatter
- Paste JSON or open a UTF-8 .json file.
- Choose two spaces, four spaces or compact output and select Format JSON.
- Review validation messages and explore the tree before copying or downloading the result.
Inspect an order without changing its IDs
The postal code stays "00123", paid stays true, and the order remains a JSON object.
Load this exact example ↗What changes—and what stays
Duplicate keys are rejected to avoid silently dropping a value. Unsafe integers and numeric literals that would change decimal value are rejected. Formatting preserves the parsed data, but numeric spelling may normalize.
Practical limits
Up to 1 MiB per input, 80 nested levels and 50,000 structured values. CSV supports 10,000 data rows and 200 columns. JSON comparison returns at most 5,000 differences. UTF-8 files only; large jobs stop after six seconds.
Common questions
Will this automatically repair invalid JSON?
No. It reports an error and its location so you can decide the intended value. Comments and trailing commas must be removed deliberately.
Can I format very long identifiers?
Quote identifiers as strings when every digit matters. The formatter rejects numbers that cannot safely round-trip through its number representation.