Validate JSON syntax instantly, detect formatting errors, and view formatted output.
Hop to nearby dev utilities without losing context.
Quick steps so you can get results fast.
Paste the payload, config file or API response you want to check.
The text is parsed exactly as JSON.parse would parse it in your application.
If parsing fails, the browser's error message points to the problem, usually with a position in the text.
Correct the input and validate again until it passes.
Everything you need to know about JSON Validator.
Answers to the most common devtool questions.
Each browser engine words its JSON error messages differently. The validity result is the same everywhere.
No. It checks syntax only, not whether fields have the types or names your application expects.
No. This tool runs in your browser with JavaScript, and what you type or paste is not sent to ToolzStack servers. Page visits are measured with Google Analytics, as described in the Cookie Policy.
Your input stays in the page while it is open. A few tools keep a short history or favourites in the local storage of this browser; you can clear it in the tool or in your browser settings.
Use Report a Bug on the page or the contact form, and include a sample input that shows the problem (remove anything sensitive first).