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JSON Validator

Check JSON syntax and inspect the reported root type. Find malformed quotes or commas without confusing syntax validation with JSON Schema checks.

Check whether a pasted payload can be parsed as JSON before using it in an API request or configuration. The result identifies valid syntax or reports the browser parser's error. It does not check a schema, required fields or application permissions.

  • 100% free
  • No registration
  • On your device
  • Modern browser
  1. 1Enter details
  2. 2Adjust options
  3. 3View result

Your input stays on this device for this operation. We don’t upload or store it.

About JSON Validator

Check whether a pasted payload can be parsed as JSON before using it in an API request or configuration. The result identifies valid syntax or reports the browser parser's error. It does not check a schema, required fields or application permissions.

Explicit validation action

The Validate JSON button checks the currently pasted payload.

Parser diagnostics

Malformed JSON produces the browser's syntax-error explanation.

Root summary

Successful checks report a root-type summary and top-level key count.

How to use JSON Validator

  1. 1

    Paste the payload

    Enter complete JSON in Input JSON, including any surrounding object or array brackets.

  2. 2

    Validate JSON

    Press Validate JSON to run the check on your current input.

  3. 3

    Correct and recheck

    Read the result, repair the input and press Validate JSON again; changing text alone does not rerun this check.

Formats and practical limits

Input: JSON text. Output: syntax status, parser error or a root-type/key-count summary.

  • Diagnostics depend on the browser and need not include a precise line and column.
  • A previous result remains until you press Validate JSON again. Valid syntax does not establish data accuracy.

Practical example

Compare {"age":"twenty"} with {"age":20,}. The first is valid syntax even if an API needs a number; the second has an invalid trailing comma.

Frequently Asked Questions

3 answers
Can a primitive value be valid JSON?

Yes. A string, number, boolean or null can be valid JSON without an object wrapper. The root-type summary uses JavaScript type labels; null is reported as object.

Is this a JSON Schema validator?

No. It checks parsing syntax, not required properties, field types or schema formats.

Why does my API reject JSON that passes here?

The endpoint can require particular fields, value ranges, authentication or a specific schema. Syntax validity addresses only the JSON representation.

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