JSON Validator

Check whether JSON is syntactically valid before deploying configs or debugging API responses. Paste your JSON and click Run to validate it.

  • Runs entirely in your browser
  • No data stored or sent to a server
  • Free forever — no signup
  • Instant conversion

Input and Output

Use the interactive encoder and decoder on this page to process your text.

Learn more about JSON validation

How to Validate JSON Syntax (With Examples)

JSON Validation

When to Validate JSON

Validate JSON before committing config files, pasting API responses into production systems, or debugging webhook payloads that fail to parse.

Real-World Examples

Valid: {"status":"ok","count":3}

Invalid: trailing comma {"a":1,}

Invalid: single-quoted keys from JavaScript pasted as JSON

Common Mistakes

  • Pasting JavaScript object literals (unquoted keys, comments, trailing commas)
  • Leaving BOM characters or smart quotes from copied documents
  • Assuming JSON5 or YAML syntax is valid strict JSON

Developer Tips

  • Validate in CI with jq empty file.json
  • Pair validation with formatting to spot structural issues faster

Frequently asked questions

Does this tool validate JSON Schema?

No. This checks JSON syntax only. Schema validation requires a separate JSON Schema validator.

Why does valid-looking data fail?

Common causes include trailing commas, single quotes, comments, or invisible Unicode characters in copied text.

Does validation modify my JSON?

No. Validation only reports whether the input parses successfully.