Online JSON Formatter & Validator
Format, validate and beautify JSON data with syntax highlighting and error detection.
▶About JSON Formatter
JSON (JavaScript Object Notation) is a lightweight data-interchange format widely used in REST APIs, configuration files, and data storage. This free online JSON formatter lets you beautify, validate, and minify JSON data instantly in your browser.
Features: format JSON with customizable indentation, minify JSON to reduce payload size, auto-detect and fix nested escaped JSON strings, and decode hex-encoded UTF-8 sequences. All processing happens locally — your data never leaves your device.
Common use cases: debugging API responses, cleaning up minified JSON from production logs, validating JSON config files before deployment, and converting single-line JSON into readable multi-line format for code reviews.
▶Frequently Asked Questions
▶How do I format JSON online?
Paste your raw or minified JSON into the editor, and it will be automatically formatted with proper indentation. You can also click the Format button to beautify the output.
▶Is my JSON data safe when using this tool?
Yes. All processing happens entirely in your browser using JavaScript. Your data is never uploaded to any server.
▶Can I minify JSON with this tool?
Yes. After pasting your JSON, click the Minify button to compress it into a single line, removing all unnecessary whitespace.
▶What JSON errors does the validator detect?
The validator detects syntax errors like missing commas, unmatched brackets, trailing commas, invalid escape sequences, and duplicate keys.