JSON Repair Online — Fix Invalid JSON Syntax

Repair malformed JSON with trailing commas, unquoted keys, or minor syntax issues. Review the output before production — then validate with our JSON validator.

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JSON repair — fix malformed syntax
Repair trailing commas, unquoted keys, and other common JSON mistakes. Always review output — repaired JSON may differ from author intent.

Developer notes

Repair runs automatically after you pause typing. Output must parse as valid JSON — semantic meaning is not guaranteed. Follow with the JSON validator before production commits. For clean formatting only, use the JSON formatter instead.

When teams use repair

Salvage hand-edited config snippets with trailing commas. Quick-fix logs or copy-paste accidents before validation. Unblock local testing when upstream exports slightly invalid JSON.

Examples

Trailing comma

Broken input

{ "users": [ {"id": 1, "name": "Ada", "role": "admin",}, {"id": 2, "name": "Grace", "role": "editor",}, ], "meta": {"count": 2, "version": "1.0",}, "flags": {"canary": true, "darkMode": false,}, }

Repaired output

{ "users": [ {"id": 1, "name": "Ada", "role": "admin"}, {"id": 2, "name": "Grace", "role": "editor"} ], "meta": {"count": 2, "version": "1.0"}, "flags": {"canary": true, "darkMode": false} }

Unquoted keys

Broken input

{ "items": [{"id": 1, "label": "alpha",},], "enabled": true, }

Repaired output

{ "items": [{"id": 1, "label": "alpha"}], "enabled": true }

Next steps

Browse the JSON tools hub. Validate repaired JSON with the JSON validator, prettify via the JSON formatter, or compare versions with JSON diff.

JSON repair FAQ

Syntax fixes, not semantic guarantees

Can repair change meaning?

Yes — it fixes syntax, not business logic. Review diffs before shipping.

What if repair fails?

Use the JSON validator for precise error locations — some payloads need manual editing.

Is data uploaded?

Never — jsonrepair runs locally after dynamic import.

JSON Tools

Validate, format, diff and explore JSON payloads — complementary to minifiers and converters.

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