JSON Validator
Instantly validate JSON syntax, identify errors with exact line and column locations, and fix formatting bugs. · Updated
Strict JSON validation with line/column pointers turns cryptic parse failures into fixable edits. Local validation is ideal for secrets-bearing API responses.
Common errors and fixes
Unexpected token }
Remove a trailing comma before the closing brace.
Unexpected end of JSON input
Close open strings, arrays, or objects; the payload is truncated.
Expected property name
JSON keys must use double quotes, not single quotes.
Unexpected non-whitespace character
Paste a single JSON value with no trailing commentary.
Options
| Option | Description |
|---|---|
| Validation Mode | Choose whether to output clean formatted JSON, compressed JSON, or a validation confirmation summary. |
| Indent Size | Number of spaces per indentation level when beautifying. |
FAQ
How does the JSON validator detect errors?
The validator parses your JSON client-side using JavaScript parsing engines and analyzes syntax tokens to pinpoint exact line and column numbers.
What are the most common JSON syntax errors?
Trailing commas after the last array item or object property, unquoted property keys, single quotes instead of double quotes, and unescaped newline characters.
Can this validator format and beautify the JSON if valid?
Yes. By default it automatically beautifies valid JSON with clean 2-space indentation. You can switch to Compact or Validate-Only mode in options.