Free JSON Validator

Check whether your JSON is valid and pinpoint syntax errors instantly.

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  • ⚡ Converted in your browser
  • ✅ No account required

JSON Validator: The Complete Guide

Paste your JSON to instantly check whether it's valid. If something is wrong, you'll get a clear error message; if it's correct, you'll see a summary of the structure.

How to use the JSON Validator

  1. Paste or type your code, text, or data into the input box.
  2. Adjust options such as indent size, dialect, or flags when the tool offers them.
  3. The output updates instantly — copy it to your clipboard or download the file.

Features

  • Instant valid / invalid result
  • Clear, position-aware error messages
  • Structure summary (type & key count)
  • 100% in-browser — nothing uploaded

Why use this tool

  • Catch trailing commas and missing quotes fast
  • Validate API payloads before shipping
  • Confirm config files parse correctly

What does a JSON validator do?

A JSON validator parses your text against the JSON specification and reports whether it is syntactically correct. It catches common mistakes such as trailing commas, single quotes, unquoted keys, and unbalanced brackets — and points you to where the problem is so you can fix it quickly.

Frequently Asked Questions

What counts as invalid JSON?

Trailing commas, single quotes, unquoted keys, comments, and unbalanced brackets or braces are all invalid in strict JSON — the validator flags them.

Does valid JSON mean my data is correct?

It means the syntax is correct. It can't know whether the values themselves are right for your application.

Is it free and private?

Yes — it's 100% free with no signup, and everything runs locally in your browser, so your data is never uploaded to a server.

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