JSON Formatter & Validator
Format, minify, and validate JSON locally in your browser. Your data is never uploaded, even when it is sensitive.
How to use
- 1Paste JSONPaste an API response, configuration file, or any JSON text into the editor.
- 2Choose an actionFormat with indentation, minify into one line, or validate the syntax.
- 3Copy the resultCopy the result in one click. All processing remains on your device.
About JSON formatting and validation
JSON (JavaScript Object Notation) is the most common format for APIs and configuration files. API responses are often compressed into a single unreadable line, while hand-written JSON is prone to small mistakes such as extra commas or missing quotes. This tool can beautify, minify, or validate JSON and help locate errors.
Format applies your chosen indentation for reading and code review. Minify removes unnecessary whitespace for the smallest single-line output. Validate reports parsing errors so you can quickly find a problem.
Common uses
- Beautify single-line API responses while debugging.
- Validate configuration before committing code.
- Minify configuration for environment variables or command lines.
- Apply consistent indentation to examples and documentation.
Troubleshooting common errors
- A trailing comma appears at the end of an object or array.
- Keys or strings use single quotes instead of the required double quotes.
- The input contains comments, which standard JSON does not support.
- A bracket or quotation mark is not closed.
Everything is processed locally, making the tool safe for internal data with secrets or tokens. To place binary data in JSON, use the Base64 encoder and decoder, or read What Is Base64?.
Frequently asked questions
QWill my JSON be uploaded?
No. Formatting, minifying, and validation happen entirely in your browser. Your data never leaves your device, making this suitable for sensitive or internal data.
QWhat is the difference between formatting and minifying?
Formatting adds indentation for readability. Minifying removes unnecessary whitespace to create compact, single-line JSON for storage or transfer.
QWhat happens when the JSON is invalid?
The tool shows the parsing error, usually with its location, so you can find issues such as extra commas or missing quotes.
QHow large can the JSON be?
The limit depends on browser memory. Normal configuration files and API responses work well, while very large inputs may be slower.
QDo I need to sign up or pay?
No. The tool is completely free and requires no account.