JSON Validator
Donfig's JSON validator catches every syntax issue in your input and pinpoints the line and column where it failed. Paste your JSON below — the status chip turns green for valid input and red with a position-aware error when something's wrong. Each error message includes a context snippet around the failure point so you can see exactly which character broke the parse. Click Repair to auto-fix common issues like trailing commas, missing quotes, or single-quoted strings. The validator follows RFC 8259 strictly; loose JSON5 features like comments are flagged as errors so you can decide whether to convert.
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Frequently asked
Which JSON specification does Donfig follow?
RFC 8259, the IETF standard. Strictly: no trailing commas, no comments, double-quoted keys and strings only.
What's the difference between validation and repair?
Validation reports problems; repair attempts to fix common ones. Use the Repair button when the input is broken on purpose (legacy data, hand-edited files).
Will it catch logical issues, like missing keys?
No, only syntax. For schema validation against an OpenAPI/JSON Schema, you'll need a separate tool.