How to use it
Review API payloads and configuration files while keeping syntax errors, duplicate names, line endings, and precision risks visible.
- Paste strict JSON into the input editor.
- Choose validation, formatting, or minification plus indentation and line endings.
- Review errors or duplicate-key warnings, then copy or download valid output.
Worked example
- Input
{"id":9007199254740993,"active":true}
- Output
{
"id": 9007199254740993,
"active": true
}
Formatting adds insignificant whitespace but preserves every digit in the original number token.
Method and definitions
- Validation follows RFC 8259: comments, trailing commas, single quotes, NaN, and Infinity are rejected.
- Formatting edits whitespace around validated tokens; minification concatenates validated token lexemes.
- Duplicate member names are a warning because RFC 8259 describes their interoperability risk.
Limits and edge cases
- The tool does not repair invalid JSON, sort keys, fetch URLs, or validate JSON Schema.
- Maximum input is 5 MiB UTF-8 and maximum structural nesting is 512.
- A valid JSON number can still exceed the precision of a later consumer; this tool preserves text but cannot control other software.
Privacy
JSON processing runs in memory in this tab. Payloads are not uploaded, shared through URLs, or saved automatically.
Sources
