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SparkJSONOnline JSON Parser
Online JSON Parser
Parse JSON strictly and surface the first syntax break with location details.
Free SparkJSON tool — runs 100% in your browser. No signup, no upload, no paywall. This page opens in validate mode.
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Strict parse for debugging
Reject JS object literals early so you fix payloads before the backend sees them. SparkJSON follows RFC 8259 grammar for what counts as valid JSON text.
- Strict — RFC 8259-oriented JSON, not JS literals.
Frequently asked questions
Why does my JS object fail?
Unquoted keys, single quotes, or trailing commas are not JSON.