Missing Closing Brace in JSON – Find and Fix }

A JSON object opened with { must eventually close with }. If the source ends or a different delimiter appears first, the parser can report an unexpected end or mismatched structure.

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Paste malformed JSON or AI-generated structured output.

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Common invalid JSON examples

Load one broken syntax pattern at a time, run the repair, and compare the declared rule with the resulting repair log.

Trailing commas

Trailing comma

Remove commas that appear immediately before closing object or array delimiters without touching commas stored inside string values.

{"roles":["admin","editor",],"active":true,}

Review: Confirm that each removed comma was only formatting punctuation and did not represent an intentionally missing value.

JavaScript-style object

Trailing comma · Single-quoted string · Unquoted object key

Convert identifier-like keys and single-quoted strings from a JavaScript object literal into standard JSON syntax.

{
  name: 'VetaTool',
  features: ['repair', 'diff',],
}

Review: Review every inferred key and string boundary because apostrophes and JavaScript escaping can make the intended text ambiguous.

JavaScript comments

JavaScript comment

Remove line and block comments that are legal in some configuration formats but are not allowed by the JSON grammar.

{
  // feature flag
  "enabled": true /* temporary rollout */
}

Review: Check whether a removed comment contained operational context that should be preserved outside the repaired JSON document.

Markdown code fence

Markdown code fence

Strip one outer Markdown fence commonly added around JSON returned by chat assistants, documentation, or copied code blocks.

```json
{"name":"Ada","active":true}
```

Review: Verify that the fence wrapped the entire payload and that no explanatory prose outside the code block was discarded.

Unsupported JavaScript literals

Undefined value · Non-finite number

Replace undefined and non-finite numbers that JavaScript accepts but standard JSON cannot represent with reviewable null placeholders.

{"missing":undefined,"score":NaN,"limit":Infinity}

Review: Decide whether null is the correct business value, or whether the property should be removed or represented another way.

Missing and redundant commas

Missing comma · Redundant comma

Insert a separator between adjacent complete values and remove extra separators only where surrounding tokens identify the boundary.

{"first":1 "second":2,,"third":3}

Review: Confirm that inferred separators match the intended property boundaries and that no omitted value was represented by an empty slot.

Mismatched delimiters

Mismatched delimiter

Replace or add a closing brace or bracket when the nested token stack identifies one bounded structural mismatch.

{"items":[1,2,3}

Review: Inspect the surrounding nesting because heavily damaged objects can have more than one plausible brace or bracket completion.

Escaped JSON string

Escaped JSON string

Decode one outer JSON string layer when a field contains an escaped object or array instead of a directly nested JSON value.

{"payload":"{\"name\":\"Ada\",\"active\":true}"}

Review: Confirm that the field is intended to become a nested object rather than remain a string consumed by another downstream system.

Repair log

Run the repair to see each change and why it was made.

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JSON delimiter repair

How to close an unfinished JSON object

Nested JSON objects must close in the reverse order they were opened. The repair tool tracks the delimiter stack and can add or replace one bounded closing delimiter, but the structural change remains review-required because heavily damaged nesting can have more than one plausible completion. This tool is free to use. No account or payment is required.

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What you can do here

  • Browser-local JSON processing
  • Route-specific malformed JSON example
  • Focused parser or repair guidance
  • Broken and corrected JSON example
  • Related JSON problem navigation
  • Mismatched delimiter repair review

Steps

  1. Paste the incomplete object or use the preloaded nested example.
  2. Run JSON Repair and inspect the mismatched-delimiter change.
  3. Confirm the source was not truncated before accepting the inserted closing brace.

Count structure, not just brace characters

Brace characters inside quoted strings are data and do not open or close JSON objects. A useful repair follows parsed string boundaries and the nested delimiter stack instead of simply counting characters.

A syntactically closed object can still be incomplete data

If bytes were lost from an API response or file, inserting } may make JSON.parse succeed while fields are still missing. Verify the producer and response length when truncation is possible.

Missing closing brace example

The inner object closes, but the outer root object remains open.

Incomplete JSON

{"user":{"name":"Ada"}

Repaired JSON

{"user":{"name":"Ada"}}

Common questions

Frequently asked questions

How do I find a missing } in JSON?

Track the nested objects that were opened outside strings and confirm each { has a matching } in the correct nesting order.

Can a missing brace cause Unexpected end of JSON input?

Yes. If the source ends while an object is still open, the parser reaches the end while waiting for a closing brace.

Is adding the final brace always safe?

No. A truncated source may contain missing values as well as missing punctuation, so confirm the payload is complete before treating a delimiter repair as sufficient.

Recommended next steps

Unexpected End of JSON InputDiagnose JSON that stops before all strings, arrays, or objects are complete.Missing Closing Bracket in JSONRepair an array that ends before its required closing bracket.JSON Repair Online – Fix Invalid JSONApply conservative syntax repairs and review every reported change.

Debugging a specific JSON issue? Browse JSON troubleshooting.