No subscription. No forced signup.

Free JSON Validator

Check JSON syntax and get a clear error location.

About the JSON Validator

JSON Validator is a free online tool from Tool Marry. Check JSON syntax and get a clear error location. There is nothing to install and no account to create — open the page, paste your input and get your result straight away. It works the same on desktop, tablet and mobile, and it sits alongside the rest of our developer tools so you can move from one job to the next without switching apps.

How to use the JSON Validator

  1. 1Open JSON Validator and paste your input.
  2. 2Adjust the available options to match what you need.
  3. 3Run the tool and review the result.
  4. 4Copy or download your output — that's it.

Frequently asked questions

Is the JSON Validator free to use?

Yes. It is completely free with no signup, no email gate and no usage limit for normal personal or business use.

Do I need to create an account?

No account is required. Open the tool and use it immediately — everything is completely free.

Is my data safe?

We keep processing as close to your browser as possible and never sell or share what you enter. Nothing you type is used for advertising.

Can I use JSON Validator on my phone?

Yes. The whole site is responsive, so the tool works in any modern mobile or desktop browser.