Developer
Validate JSON Online
- Browser-based
- No signup
Validate JSON online before sending API requests or committing config files. Paste JSON to confirm it parses, highlight error location, and fix trailing commas or quote issues fast.
JSON requires double quotes on keys and strings; single quotes and comments are invalid in strict JSON.
100% Client-Side
Your data never leaves your computer.
How to use this tool
Paste JSON into the editor. Fix reported errors until validation passes, then copy clean JSON.
Worked example
Example: API returns 400—validator shows a trailing comma on line 14 before you redeploy.
When to use this
- Debugging webhook payloads.
- Checking exported config before production.
- Learning JSON syntax in tutorials.
Common mistakes
- Trailing commas after last array/object item.
- Unescaped newlines inside strings.
- Using undefined or NaN (invalid in JSON).
Related long-tail tasks
- json lint online
- validate json file
- json parse error line number
How it works
Paste JSON to validate syntax instantly. Invalid JSON shows parse errors with line and column when available. Validation runs entirely in your browser.
Limitations
Validates JSON syntax only. Schema, business rules, and duplicate keys are not checked unless noted.
Privacy and file handling
Your data is processed in your browser and is not uploaded to our server.
Related JSON Validator guides
These pages use the same json validator with guides tailored to specific search intents.
- JSON Validator — general payment estimate
- JSON Syntax Checker
- Validate JSON Syntax
- JSON Lint Checker
- Check JSON Online
Frequently asked questions
Does this format JSON?
Use JSON Formatter for pretty-print; this tool focuses on validity.
JSON5 or comments?
Standard JSON only—comments and unquoted keys will fail validation.
Large files?
Very large payloads may slow the browser; validate samples or use CLI for huge files.
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