JSON Validator
Validate JSON syntax with precise error details. Runs in your browser — no data sent anywhere.
Ctrl+Enter to validate
About JSON
Why is my JSON invalid?
The most common JSON errors are: trailing commas after the last item (e.g.
{"a": 1,}), single quotes instead of double quotes, unquoted property keys, and missing commas between items. The validator highlights the exact line and column.Does JSON support comments?
No. Standard JSON does not support
// comments or /* block comments */. If you see these in a config file, it's likely JSONC (JSON with Comments), used by tools like VS Code — but not valid for standard JSON parsers or webhook payloads.Can JSON keys be unquoted?
No. All JSON keys must be double-quoted strings.
{"key": "value"} is valid — {key: "value"} is not. This differs from JavaScript object literals, which allow unquoted keys.Why do webhook payloads sometimes fail JSON parsing?
Some services send webhook payloads with incorrect Content-Type headers, double-encoded values, or non-standard encoding. Always validate the raw payload before processing. HookDeploy's request inspector shows the raw payload exactly as received.
Debugging webhook payloads?
HookDeploy captures every webhook with full headers and body, so you can inspect and replay them without copy-pasting JSON manually.