Format, validate, minify, and compare JSON instantly. Everything runs in your browser -- nothing is uploaded to any server.
100% Private Instant No Limits
Invalid JSON
Valid JSON
Input
Output
Error
Left (Original)
Right (Modified)
Diff Result
How It Works
Paste Your JSON
Paste raw JSON into the input panel, or switch to Diff Compare mode to compare two JSON objects side by side.
Format, Minify, or Validate
Click Format for pretty-printed output with syntax highlighting, Minify to compress, or Validate to check for errors.
Copy or Download
Copy the result to your clipboard or download it as a .json file. Everything happens locally in your browser.
Frequently Asked Questions
JSON (JavaScript Object Notation) is a lightweight data format used by virtually every web API and modern application. Formatted JSON uses indentation and line breaks to make nested structures readable, which is essential for debugging API responses, editing config files, and reviewing data.
Your data never leaves your device. All formatting, validation, and diff operations run entirely in your browser using JavaScript. No data is sent to any server, stored, or logged. This makes the tool safe for sensitive API keys, tokens, and private data.
Format (pretty-print) adds indentation and line breaks to make JSON human-readable. Minify does the opposite -- it strips all whitespace to produce the smallest possible output. Minified JSON is ideal for APIs and storage where file size matters.
Diff Compare lets you paste two JSON objects and see a line-by-line comparison. Added lines are highlighted in green, removed lines in red, and unchanged lines remain dimmed. It's useful for comparing API responses, spotting config changes, and reviewing data migrations.