JSON Formatter, Validator and Format Checker
Paste or test JSON online to check syntax, locate errors, format or compact the document, and inspect nested data in a tree view.
Processed locally in your browser; data is not uploaded
Features
- Format and compact JSON
- Syntax validation
- Tree view
- Convert JSON to YAML/XML/CSV/JS/Kotlin/Java/Go
- Local browser processing
FAQ
How can I test whether JSON is valid online?
Paste the JSON and choose Format or Validate. The checker reports syntax errors with their line and column when available.
Does the JSON checker show the error location?
Yes. Invalid JSON is reported with a line, column and nearby source context to help you fix it.
Is my JSON uploaded?
No. Formatting and validation run locally in your browser.