JSON Validator - JSON Syntax Checker

What is JSON Validator?

JSON Validator checks whether JSON text syntax is correct. It uses Go's `encoding/json` package to calculate accurate error positions (line, column). Use it for debugging API responses, validating configuration files, and checking data input.

See also: JSON Formatter · JSON Diff · JSON Tree Viewer

How to Use

1. Paste JSON into the text area
2. Click the 'Validate' button
3. If there are errors, the line and column numbers are displayed. Click to jump to the error location

Usage Examples

Valid JSON:
{"name":"John Smith","age":30,"active":true}

Invalid JSON (missing comma):
{"name":"John Smith"
"age":30}
→ Error: near line 2, column 1

Practical use: Quickly check whether the JSON in a REST API request body has correct syntax

FAQ

Can it validate against a JSON Schema?

No. This tool only checks JSON syntax. Validation against JSON Schema (types, values, etc.) is not supported.

Are multiple errors detected?

Validation stops at the first error, following the behavior of Go's encoding/json package. Fix the error and re-validate.

Is my data sent to a server?

Yes. Validation is processed by the Go backend (Lambda). However, input data is not stored on the server.

Can it validate large JSON?

JSON up to 10MB can be validated. Inputs exceeding 10MB will result in an error.

What happens when I click on the error line?

The input text area scrolls to the error line and focus moves there.

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