JSON Validator
Validate JSON syntax, detect common issues, and inspect structure — entirely in your browser.
About JSON Validator
Paste JSON to instantly validate syntax against the JSON specification. Get precise line and column error locations, detect common pitfalls like trailing commas and comments, and view a structure summary showing key counts, nesting depth, and value types — all processed locally.
Features
- Validate JSON syntax with precise error locations
- Detect trailing commas, comments, and single-quoted strings
- Display line and column numbers for each issue
- Inspect structure: key count, depth, and value types
- Distinguish errors from warnings for non-standard patterns
- Load sample JSON to test the validator
- 100% client-side — your data never leaves your device
How to use
- 1Paste or type JSON into the input area.
- 2Click Validate to check syntax and structure.
- 3Review errors, warnings, and structure stats below.
Frequently Asked Questions
What's the difference between this and JSON Prettier?
JSON Prettier focuses on formatting and beautifying valid JSON. The JSON Validator provides detailed error diagnostics, warnings for non-standard patterns, and structure analysis.
Does it detect trailing commas?
Yes. Trailing commas are flagged as warnings since they're not allowed in strict JSON, even though some parsers accept them.
Can it validate JSON with comments?
Comments are not valid JSON. The validator flags them as warnings and reports the exact location so you can remove them.
Is my JSON sent anywhere?
No. Validation runs entirely in your browser. Nothing is uploaded or stored.
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