JSON Formatter + Tree Viewer

Format, validate, and visualize JSON data with syntax highlighting, tree view, and real-time error detection. Runs entirely in your browser.

100% client-side — your data never leaves your browser

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JSON Formatter and Validator Online

Paste your JSON to format, validate, and explore it with syntax highlighting. Switch between formatted text and an interactive tree view. Everything runs client-side.

How to Use

  1. Paste JSON into the input editor on the left
  2. Format or Minify using the buttons in the toolbar
  3. View the output as formatted text or switch to Tree view
  4. Adjust indentation with the dropdown (2 spaces, 4 spaces, or tabs)
  5. Copy the formatted result with one click

Features

Syntax Highlighting

The editor provides full JSON syntax highlighting powered by CodeMirror 6, with bracket matching, line numbers, and active line highlighting. The dark theme is designed for comfortable reading.

Real-Time Validation

JSON is validated as you type. Errors are shown with descriptive messages and position information, so you can quickly find and fix issues like missing commas, unclosed brackets, or invalid values.

Tree View

The interactive tree view lets you expand and collapse objects and arrays to explore deeply nested structures. Values are color-coded by type: strings in green, numbers in blue, booleans in orange, and null in gray.

Minification

The minify function removes all whitespace from valid JSON, producing the most compact representation. This is useful when you need to reduce payload size for API requests or storage.