JSON Validator
Validate JSON syntax, locate parser errors, and inspect document structure directly in your browser.
Validate JSON syntax
Paste JSON, pinpoint syntax errors, and inspect parsed structure locally in your browser.
Validation Result
Document summary
- Root type
- —
- Total values
- 0
- Objects
- 0
- Arrays
- 0
- Properties
- 0
- Array items
- 0
- Container depth
- 0
Your JSON is validated locally in your browser and is not sent to a server.
Overview
What is a JSON validator?
A JSON validator checks whether text follows the JSON grammar. It helps identify syntax problems before JSON is used in an API request, configuration file, test fixture, or application.
This tool is a JSON syntax checker. It uses the browser JSON parser and reports the parsing error when the input is invalid. It also shows the nearest line and column, a source excerpt, and a cautious suggestion for common error patterns.
Valid documents receive a structural summary covering the root type, total values, objects, arrays, properties, array items, and container depth. This summary describes parsed structure; it does not replace JSON Schema or application validation.
Steps
How to validate JSON
- Paste JSON into the JSON Input field.
- Select Validate JSON.
- Review the validation result, document summary, or reported syntax error.
- Fix the error, then validate the JSON again.
Troubleshooting
Common JSON syntax errors
- Trailing commas: the final property or array item cannot end with a comma.
- Missing quotes: object property names must use double quotes.
- Single quotes: JSON strings require double quotes, not single quotes.
- Missing values: every property name must be followed by a valid JSON value.
- Unmatched braces or brackets: every opening delimiter needs a matching closing delimiter.
- Comments: standard JSON does not allow line or block comments.
- Invalid escapes: a backslash in a string must introduce a supported JSON escape.
Diagnostics
How JSON error diagnostics work
The browser parser supplies the authoritative syntax result. When possible, Orbilyra converts its position into a line and column and shows the nearby source without rendering the input as HTML.
The likely-cause message is a focused troubleshooting hint, not a second parser. Parser messages vary between browsers, and the reported position is often where parsing stopped rather than where the original mistake began.
| Invalid pattern | Likely cause | Typical fix |
|---|---|---|
{"active": true,} | Trailing comma | Remove the comma before }. |
{'name': 'Ada'} | Single quotes | Use double quotes for keys and strings. |
{name: "Ada"} | Unquoted key | Write {"name": "Ada"}. |
{"count": } | Missing value | Add a valid value after the colon. |
Examples
Valid and invalid JSON examples
Valid JSON
{
"name": "Orbilyra",
"valid": true
}Invalid JSON
{
"name": "Orbilyra",
"valid": true,
}Technical notes
What valid JSON does not guarantee
- Required fields, field types, ranges, and formats still need schema or application rules.
- A syntactically valid document can contain unexpected, unsafe, or untrusted data.
- Duplicate object names may parse, but consumers can disagree about how to handle them.
- Standard JSON excludes comments, undefined, NaN, Infinity, functions, and trailing commas.
Comparison
JSON Validator vs JSON Formatter
JSON Validator focuses on checking syntax and exposing parsing errors. JSON Formatter focuses on beautifying and minifying valid JSON.
If your JSON is valid and you want to make it easier to read or more compact, use theJSON Formatter.
Scope
JSON syntax vs JSON Schema
Syntax validation checks whether JSON follows the JSON grammar. Schema validation checks whether parsed data matches a specified structure, data type, and set of rules.
This tool validates syntax only. It does not validate JSON Schema, API contracts, or business-specific field requirements.
Workflows
When to validate JSON syntax
- Check a request body before sending it to an API.
- Diagnose copied configuration data that fails to parse.
- Find trailing commas, invalid quotes, missing values, or unmatched delimiters.
- Confirm syntax before applying separate JSON Schema or business-rule validation.
FAQ
Frequently asked questions
What is a JSON validator?
A JSON validator checks whether text follows JSON syntax, including valid quoting, values, commas, braces, and brackets.
Does this validator upload my JSON?
No. Validation happens locally in your browser, and this tool does not send your JSON to a server.
What JSON errors can this tool detect?
It detects syntax errors reported by the browser JSON parser, such as trailing commas, invalid quotes, missing values, and unmatched braces or brackets.
Does this validate JSON Schema?
No. This tool validates JSON syntax only. It does not check JSON Schema, API contracts, or business field rules.
What is the difference between a JSON validator and formatter?
A validator focuses on syntax correctness and parsing errors. A formatter focuses on making valid JSON readable or compact.
Why is a trailing comma invalid in JSON?
The JSON grammar does not allow a comma after the final property in an object or the final item in an array.
Why can the highlighted position appear after the real mistake?
A parser reports where it could no longer continue. The original mistake may be an earlier quote, comma, colon, brace, or bracket, so inspect the highlighted token and the characters immediately before it.
Why can valid JSON still be rejected by an API?
Syntax validation only proves that the text can be parsed. An API may separately require specific fields, data types, formats, authentication, or business rules.
Does this tool detect duplicate object property names?
No. Duplicate names may parse successfully, and parser behavior can make earlier values inaccessible. Use schema or application-specific checks when property uniqueness matters.