Missing Colon in JSON – Locate the Syntax Error

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Every JSON object member uses a colon between its quoted key and value. When the colon is missing, the parser usually fails as soon as it reaches the value that follows the key.

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36 chars · 4 lines

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Invalid JSONExpected ':' after property name
Line 2Column 10Character 12Found “"”
"name" "Ada",
The highlighted character is where JSON parsing stopped.

JSON object syntax error

How to locate a missing property colon

JSON object members follow the form "key": value. The checker above preloads a key and string value with the colon removed so the parser position shows where the object-member grammar becomes invalid. 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

Steps

  1. Paste the invalid object and locate the key immediately before the reported value.
  2. Confirm that the key is double quoted and should be paired with that value.
  3. Insert a colon between the key and value, then validate the whole document again.

Colon and comma errors describe different boundaries

A colon belongs inside one object member between its name and value. A comma belongs between two complete members. Checking which boundary is broken prevents adding the wrong punctuation near the reported token.

Inspect nearby quotes before adding punctuation

If the key quotation mark is missing or the value is an unterminated string, inserting a colon alone will not repair the document. Use the error context to confirm the surrounding tokens first.

Missing colon example

The quoted name key is followed directly by its string value.

Invalid JSON

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

Valid JSON

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

Common questions

Frequently asked questions

Where does a colon go in JSON?

Inside an object member, the colon appears immediately after the quoted key and before its value: "key": value.

Is a missing colon the same as a missing comma?

No. Colons connect keys to values, while commas separate complete object members or array items.

Why might the parser highlight the value?

After reading a property name, the parser expects a colon. The following value is the first token that proves the required separator is missing.

Recommended next steps

Missing Comma in JSONLocate adjacent properties or array values that need a separator.Unquoted Keys in JSONAdd required double quotes around JavaScript-style object keys.JSON Error Checker Online – Find Syntax ErrorsLocate parser failures with line, column, character position, and nearby source context.

Debugging a specific JSON issue? Browse JSON troubleshooting.