JSON Validator

Check whether JSON is valid and see exactly what's wrong if not.

JSON to validate

Result

Runs entirely in your browser — nothing here is uploaded anywhere.

How it works

  1. Paste your JSON into the input box.
  2. It's parsed immediately.
  3. See a valid/invalid result with details.

Need more than a one-off tool?

Velox PDF for Mac keeps every tool like this — plus AI chat, summarization, and semantic search across your documents — in one native app, working offline for markup and signing.

Download Velox PDF for Mac — free →

Frequently asked questions

What does this tool check?

Whether the text is syntactically valid JSON — matching brackets, quoted keys, no trailing commas, etc. It doesn't check against a specific schema.

Is my data uploaded?

No — validation happens entirely client-side in your browser.