Free Online JSON Formatter
Format, validate & beautify JSON data
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About this tool
Format, validate, and beautify your JSON data instantly with this free online JSON formatter. Paste raw or minified JSON and get a cleanly indented, syntax-highlighted output that is easy to read and debug. The tool validates your input in real time and shows precise error messages — missing commas, trailing commas, unquoted keys, mismatched brackets — so you can fix problems quickly without guessing. Switch between 2-space and 4-space indentation to match your project's style guide, or minify the JSON to a single compact line for use in API payloads, configuration files, and data transfers where size matters. Syntax highlighting color-codes strings, numbers, booleans, and null values so you can scan the structure at a glance. The formatter handles deeply nested objects and large arrays without slowing down. Common use cases include debugging API responses from tools like Postman or curl, cleaning up configuration files, preparing test fixtures, and inspecting webhook payloads. All processing happens entirely in your browser — your data is never sent to a server or stored anywhere. Whether you are a front-end developer, back-end engineer, or data analyst, this tool makes working with JSON faster and less error-prone.
Frequently Asked Questions
JSON (JavaScript Object Notation) is a lightweight data format used for exchanging data between a server and a web application. It's human-readable and widely used in APIs, configuration files, and data storage.
Common JSON errors include missing commas between items, trailing commas after the last item, single quotes instead of double quotes, and unquoted keys. Our validator highlights exactly where the error occurs so you can fix it quickly.
Formatting (beautifying) adds indentation and line breaks to make JSON readable. Minifying removes all unnecessary whitespace to reduce file size — useful for production code and API payloads.
Yes. All processing happens entirely in your browser. Your JSON data is never sent to any server or stored anywhere. It stays completely private on your device.
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