Is "hello" valid JSON?

Yes. A quoted string like "hello" is valid JSON. However, hello without quotes is not valid JSON.

Is {key: "value"} valid JSON?

No. JSON requires all keys to be double-quoted strings. The correct form is {"key": "value"}.

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Is This Valid JSON?

Not sure if what you have is valid JSON? Paste it into FixTools. If it is valid, you get a green confirmation. If it is not, you get the exact error location and a plain-language explanation. No need to fire up a terminal or write a test script.

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Error location for invalid JSON

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Validates any JSON type

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JSON Validator

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How to use this tool

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Paste whatever you think might be JSON and click Validate to find out.

How It Works

Step-by-step guide to is this valid json?:

1
Paste the suspect JSON
Copy whatever you think might be JSON and paste it into the editor.
2
Click Validate
FixTools checks whether it is valid JSON and tells you immediately.
3
Act on the result
If valid: format it or use it as is. If invalid: read the error message and fix it.