JSON Validator
Check whether your JSON is valid, with a clear error message pointing out exactly what's wrong.
Runs entirely in your browser — your files are never uploaded to a server.
This tool runs entirely in your browser. Your JSON data is never uploaded to our servers.
How It Works
1. Choose Your File
Drag & drop or select the file you want to work with.
2. Processed in Your Browser
Everything happens locally on your device — your file is never uploaded anywhere.
3. Download Your Result
Get your finished file instantly, ready to save or share.
Frequently Asked Questions
What happens if my JSON is invalid?
You'll see a clear error message describing what's wrong, such as a missing comma or unclosed bracket.
Can I also format valid JSON with this tool?
Yes — once your JSON validates, it's automatically shown neatly formatted below.
Is this tool accurate?
Yes, it uses your browser's native JSON parser — the same engine used by JavaScript itself.