A result in three steps
- 01
Paste JSON data.
- 02
Choose pretty or minified output.
- 03
Copy the validated result.
09
Data & developer
JSON Formatter & Validator
Validates JSON syntax in the browser and produces readable, indented output. Parse errors are surfaced without sending the payload anywhere.
✓ Free✓ No account✓ In-browser
Result
Your result will appear here.
When is this tool useful?
- ✓ Inspecting API responses
- ✓ Editing config files
- ✓ Finding malformed JSON
Important limitation
Automated output is a preliminary assessment. Do not use it alone for legal, financial, medical, or security-critical decisions.
ABOUT THIS TOOL
Frequently asked questions
Does this tool send input to a server?+
No. Processing runs in this browser tab. Data leaves the page only when you choose to copy or download the result.
Is the result definitive?+
The tool produces consistent output from disclosed rules and browser APIs, but context, data quality, and method limitations can affect it. Verify high-impact decisions.
Is input saved?+
No. Tool input is not persisted to localStorage or another durable store. Only a non-sensitive tool-usage count may be kept on this device for personalized home-page shortcuts.