JSON Validator
JSON Validator: free, instant and private. Formatting is done with the browser’s own JSON parser, so you get a real syntax error with the exact position instead of a guess.
How the JSON Validator works
The JSON Validator takes JSON and returns the answer instantly — no button to hunt for, no page reload. Formatting is done with the browser’s own JSON parser, so you get a real syntax error with the exact position instead of a guess. Your data never leaves the page, which matters for API responses and config files.
Enter your own numbers to replace the example values; the result panel updates as you type. Everything runs in this single page, so nothing you enter leaves your device.
Formula used
JSON.parse → JSON.stringify with an indent of 2 spaces
| Symbol | Meaning |
|---|---|
| input | a JSON object, array or snippet |
Formatting is done with the browser’s own JSON parser, so you get a real syntax error with the exact position instead of a guess. Your data never leaves the page, which matters for API responses and config files.
Inputs used: JSON.
Worked example
Take the default example — json of {"site":"ToolFactory","tools":[{"id":"emi-calculator","type":"CALC"}],"live":true}:
- output: { "site": "ToolFactory", "tools": [ { "id": "emi-calculator", "type": "CALC" } ], "live": true }
Frequently asked questions
- What formula does the JSON Validator use?
- It uses JSON.parse → JSON.stringify with an indent of 2 spaces, where input is the a JSON object, array or snippet.
- Is the JSON Validator free?
- Yes. There is no signup, no usage limit and no watermark — the formatter runs entirely in your browser.
- How do I read the result?
- Formatting is done with the browser’s own JSON parser, so you get a real syntax error with the exact position instead of a guess. Your data never leaves the page, which matters for API responses and config files.
- Does the JSON Validator store or send my data?
- No. Every calculation happens locally in the page, so the numbers you type are never uploaded or logged.
- Does it work on a phone and offline?
- Yes — the page is a single lightweight file that adapts to any screen size. Once it has loaded it keeps working without a network connection.