JSON Formatter and Validator Online
Paste your JSON below to format, validate, minify, and find syntax errors instantly. Fast, browser-based, and completely private — your JSON is processed locally.
🔒 Your JSON is processed locally in your browser. We do not upload, store, or share your data.
Common JSON Errors This Tool Can Detect
| Error | Example | Fix |
|---|---|---|
| Missing comma | {"a":1 "b":2} | Add a comma between properties |
| Trailing comma | {"a":1,} | Remove the comma before } or ] |
| Unquoted property name | {a:1} | Wrap keys in double quotes |
| Single quotes | {'a':'b'} | Use double quotes for strings |
| Extra closing bracket | {"a":1}} | Remove the unmatched } or ] |
| Invalid escape character | {"a":"\x"} | Use a valid escape like \\n or \\u00e9 |
Many of these are fixed automatically by the Repairbutton. For anything it can't safely resolve, the validator points you to the exact line and column.
What is a JSON Formatter and Validator?
A JSON formatter and validator is a developer tool that does two jobs at once. It beautifies JSON by adding consistent indentation and line breaks so the structure is easy to read, and it validates the JSON by checking it against the specification and reporting any syntax errors. This tool also lets you minify JSON for compact transport and repair common mistakes automatically.
How to use this JSON formatter
- Paste your JSON into the input box (or load the sample / upload a file).
- Click Format to beautify, or Validate to check for errors.
- Check any errors by line and column — the failing line is highlighted.
- Copy or download the clean result, or switch to Tree View to explore it.
JSON Formatter vs JSON Validator
The formatter makes valid JSON readable; the validator tells you whether the JSON is valid in the first place and where it breaks. You usually want both — validate to catch the error, then format once it parses cleanly.
Is my JSON data private?
Yes. Your JSON is processed locally in your browser. We do not upload, store, or share your JSON data, so it's safe for proprietary API responses, configuration files, and other sensitive payloads.