Santekno/tools
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JSON Formatter & Validator

Format, beautify, and validate JSON instantly in your browser.

Processed in your browserUpdated · Jan 2026
Input
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Output
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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 INPUT panel
  • The output regenerates automatically as you type
  • Use Copy to put the result in your clipboard
  • Click Sample to 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.