Development

JSON Validator

Check if a JSON string is syntactically correct and identify errors.

Carregando ferramenta...

How to use

  1. 1Paste the JSON.
  2. 2Click Process.
  3. 3See if it is valid or where the error is.

About

Validates JSON syntax and points to the exact error, essential for debugging APIs and config files.

What is a JSON validator and how to use it

The JSON validator checks whether a text follows the JSON syntax rules and points out exactly where the error is. It is the first line of defense before sending data to an API or loading a configuration file.

JSON has strict rules: double-quoted keys, commas separating items, and brackets and braces closed in the right order. A single wrong character — a trailing comma or a missing quote — invalidates the entire document.

The validator analyzes the text and, if there is an error, indicates the position and type of the problem. This turns an error-hunting task into a quick, objective fix.

Validating JSON is different from validating against a schema. Here, the tool only confirms whether the syntax is correct; checking required fields and expected types requires a schema (JSON Schema).

Examples

  • Input: {"name":"Ana"} → Output: valid JSON.
  • Input: {"name":"Ana",} → Output: Could not process this data. Please check the format provided.

Limitations

  • The validator checks only syntax, not semantics or schema compliance.
  • Very large files can freeze the browser during analysis; for those cases, use a command-line tool.

How to use the JSON validator

  1. 1Paste the JSON into the main field.
  2. 2Click Process to validate.
  3. 3Read the result: valid, or the position of the error.

Frequently asked questions

What is the difference between validating syntax and validating a schema?

Syntax checks whether the JSON is well written. Schema checks whether it has the expected fields and types. This tool validates only syntax.

Does the validator accept single-quoted keys?

No. The JSON standard requires double quotes. Single quotes are common in JavaScript but invalid in JSON.

Is my JSON sent to any server?

No. Validation happens 100% in the browser, and your content never leaves the device.

Other tools

UUID Generator

Generate random UUIDs instantly.

JSON Formatter

Format and validate JSON with automatic indentation.

Base64 Encode/Decode

Encode and decode text in Base64.

URL Encode/Decode

Encode and decode URLs.

UTM Builder

Build and validate campaign URLs with UTM parameters.

JSON Minifier

Compact JSON by removing spaces.