Unescaped Newline in JSON – Escape Line Breaks Correctly

Local processing

A JSON string cannot contain a literal line break. Newlines inside a quoted value must be represented with an escape such as \n in the raw JSON text.

Indent

41 chars · 4 lines

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Invalid JSONUnescaped control character in string
Line 2Column 25Character 27Found line break
"message": "first line↵
The highlighted character is where JSON parsing stopped.

JSON string control-character error

Why literal newlines break JSON strings

Pretty-printed JSON may place line breaks between properties, but an actual line break inside a quoted string is different. Control characters in string content must use their escaped representation. This tool is free to use. No account or payment is required.

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Diagnose the problem

Why this happens

Formatting newlines and string newlines are different

Whitespace between JSON tokens can include newlines. The restriction applies only after the parser has entered a quoted string value or property name.

  • Multiline user input inserted into JSON without serialization.
  • Template output that writes raw line breaks into a quoted value.
  • Copied text pasted directly between JSON quotation marks.

Let a serializer escape text when possible

When generating JSON in code, prefer JSON.stringify or an equivalent serializer instead of manually concatenating strings. The serializer will escape embedded newline characters correctly.

Resolve the issue

Fix it step by step

  1. Locate the literal line break between the opening and closing quotes.
  2. Replace the raw newline character with \n in the JSON text when a newline belongs in the value.
  3. Validate the raw JSON before embedding it in another programming-language string.

Use the solving tool

Recommended solution

Run the focused checker with the failing payload to locate the parser error and inspect the nearby source before changing data.

Open JSON Error Checker

Unescaped newline example

The invalid value contains a literal line break; the valid version stores the same break as \n.

Invalid multiline string

{
  "message": "first line
second line"
}

Valid escaped newline

{
  "message": "first line\nsecond line"
}

Common questions

Frequently asked questions

Can formatted JSON contain newlines?

Yes, between tokens. A literal newline is invalid only when it appears inside a quoted JSON string.

How do I store multiline text in JSON?

Represent each line break with the escaped newline sequence \n in raw JSON text, or let a JSON serializer escape the string for you.

Why does the number of backslashes change in source code?

A programming-language string can add another escaping layer. Inspect the runtime JSON text to determine what JSON.parse actually receives.

Debugging a specific JSON issue? Browse JSON troubleshooting.