Home JSON Validator

JSON Validator Online

Check whether JSON is valid before it reaches your API, test suite, deployment config, or analytics pipeline. This page is tuned for syntax troubleshooting and linked repair workflows.

Paste JSON to begin.
Ctrl or Command + Enter validates JSON. 0 chars
Runs locally in your browser. Your JSON is not uploaded.

What this tool does

The validator checks whether your JSON can be parsed correctly. It helps with malformed payloads, broken config files, and copy-pasted snippets that look close to valid but fail because of one syntax rule.

Common use cases

  • Testing request bodies before sending them to an API.
  • Debugging webhook payloads from logs or browser devtools.
  • Checking application config files during deployment changes.
  • Reviewing JSON exports before passing them into another tool.

Before and after example

Invalid JSON

{
  "user": "Ada",
  "roles": ["admin", "editor",],
}

Fixed JSON

{
  "user": "Ada",
  "roles": [
    "admin",
    "editor"
  ]
}

Common JSON errors related to validation

  • Trailing commas after the final array or object item.
  • Using single quotes for strings or keys.
  • Missing closing braces or brackets in nested structures.
  • Leaving object keys unquoted after copying from JavaScript.

How to use the validator

  1. Paste JSON into the editor.
  2. Click Validate JSON to check the syntax.
  3. If the JSON is invalid, compare it with Fix Invalid JSON or Common JSON Errors.
  4. Use Format once the JSON is valid and you want a readable version.
Privacy note: Runs locally in your browser. Your JSON is not uploaded.

Related JSON tools

Fix Invalid JSON

Use the debugging-focused page for guided repair patterns and invalid input examples.

JSON Formatter

Once valid, format JSON for easier reading and sharing.

Common JSON Errors

See the most common syntax mistakes with short before-and-after fixes.

FAQ

Does the validator explain every possible JSON error?

It checks parsing validity and helps surface syntax problems quickly. Pair it with the related repair guides for concrete fixes.

Can I validate JSON files from my computer?

Yes. Upload a local .json file and the page will read it in your browser.

Why does valid JavaScript object syntax sometimes fail here?

JSON is stricter than JavaScript objects. Keys must be quoted, strings require double quotes, and trailing commas are not allowed.

Can I format or minify from this page too?

Yes. The validator includes formatting and minification actions so you can stay in one workflow.