Text & developer tools
JSON Formatter & Validator Online
Check JSON syntax and create a readable or compact copy.
Data is processed on your device · No data is uploaded to our servers
Instructions
- Paste JSON, choose formatting, then validate and format.
- Review the output and status message. Use the download button to save a copy.
Understanding your result
Formatting {"name":"Ada","active":true} changes spacing while keeping those values. Minified output removes unnecessary layout. Successful parsing means the text is valid JSON syntax; it does not check that your application's expected fields or types are present.
What to do if you have a problem
If validation fails, inspect quotes, commas and bracket pairs near the reported position. JSON requires double-quoted strings and rejects comments and trailing commas. Keep long identifiers as strings when their digits must be preserved, and inspect duplicate keys before formatting.
What to know before using the result
Maximum 500,000 characters. JavaScript JSON parsing can round numbers beyond safe integer precision and retains only the last occurrence of duplicate keys. JSON comments and trailing commas are invalid.
Files and text are held in this page while you work. Downloads are saved through your browser. Reloading or closing the tab clears the working page; a downloaded copy remains in your device's download location.
Summary
Save the formatted or minified JSON after checking the values your application needs.