UUpayaTools

Developer Tools

JSON Validator

Validate JSON syntax and inspect key counts instantly.

About this tool

Confirm whether a payload is valid JSON before sending it to an API or committing config. Get pass/fail status and helpful error details.

How to use

  1. Paste the JSON string.
  2. Click Validate.
  3. Review the status message and fix any reported issues.

Examples

  • Validate a webhook body before posting.
  • Check a theme config file for trailing commas.
  • Confirm an LLM output is valid JSON.

Benefits

  • Clear pass/fail feedback
  • Shows parse errors
  • Key count insights
  • Private and fast

Frequently asked questions

Why is my JSON invalid?+

Common issues include trailing commas, single quotes, comments, and unquoted keys — none of which are allowed in standard JSON.

Can I format after validating?+

Yes. Use our JSON Formatter to beautify valid JSON.

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