Structured data
JSON Formatter and Validator
Turn dense JSON into readable structure and catch syntax errors without uploading the document.
Processed locally. Your input and output are never uploaded.
Tool overview
Format valid JSON without hiding invalid input
The formatter parses the complete document before producing output. Invalid JSON stays untouched and reports an approximate line, column, and nearby snippet. Valid JSON can use two spaces, four spaces, or tabs; optional key sorting is clearly marked as destructive because property order changes.
Review API responses and configuration JSON
- Review API responses
- Validate configuration snippets
- Normalize JSON indentation
- Escape non-ASCII output for transport
Validate before pretty-printing
- Paste JSON or open a local .json file.
- Choose indentation and Unicode handling.
- Process the document and review its validation status.
- Copy or download the resulting .json file.
Indentation, key order, and Unicode escaping
- Indentation affects whitespace only.
- Sort keys recursively changes object property order.
- Escape Unicode writes non-ASCII characters as JSON escape sequences.
- Invalid JSON never produces a modified output.
Format valid JSON without changing values
Before
{"name":"Café","active":true}After
{
"name": "Café",
"active": true
}Comments, duplicate keys, and numeric precision
- JSON comments and trailing commas are invalid.
- Numbers beyond JavaScript safe integer precision are not preserved exactly.
- Duplicate object keys follow standard JSON.parse behavior and retain the last value.
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Questions
JSON Formatter and Validator FAQ
Is invalid JSON repaired automatically?
No. The tool reports the approximate location and leaves your source unchanged.
Does key sorting change the data?
Values remain the same, but property order changes, so it is an explicit destructive option.