How to use JSON Formatter & Validator
Paste your input on the left, choose the options you want, and the output appears instantly on the right. Everything runs in your browser — none of your data is sent to a server.
- Paste or type your input in the
INPUTpanel - The output regenerates automatically as you type
- Use
Copyto put the result in your clipboard - Click
Sampleto load a working example
What is JSON Formatter & Validator?
JSON Formatter is a free online tool that helps you format and beautify minified or compact JSON data into a human-readable structure. It also validates your JSON and highlights syntax errors with precise error messages. All processing happens locally in your browser — your data never leaves your device. This tool is part of santekno's developer toolbox — a curated collection of utilities built for engineers who care about speed, privacy, and simplicity.
Common use cases
- Debugging API payloads and integration issues
- Inspecting tokens, hashes, or encoded strings during development
- Generating fixtures and sample data for tests
- Sharing readable output with teammates in code reviews
FAQ
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate.
Yes. All JSON formatting happens entirely in your browser. No data is sent to any server.
Yes, enable the "Sort Keys" option in the settings panel to sort all object keys alphabetically.
You can choose 2 spaces, 4 spaces, or tab indentation.
Yes, up to 1MB of input is supported. For larger files, consider splitting them first.