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JSON to Dart

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JSON to Dart — Generate Dart/Flutter Models from JSON Online

What is JSON to Dart?

Generate Dart classes from JSON. Convert JSON to Dart models for Flutter or Dart apps.

Convert JSON to Dart class definitions. Use for Flutter or Dart API clients and models. Runs in your browser. Part of formatterjson.org.

How to Use JSON to Dart

  1. Paste or type your input into the editor on the left panel.
  2. Results update automatically while you type. You can also press Ctrl+Enter to force a refresh.
  3. View the result in the output panel on the right with full syntax highlighting.
  4. Use Copy or Download to export the result.
  5. Drag and drop .json or .txt files directly into the editor.
  6. Toggle Tree View for an interactive, collapsible view of the JSON structure.

Example

Input:

{"name":"John","age":30}

Output:

class Root {
  final String name;
  final num age;
  Root({name, age});
}

Common Use Cases

  • Flutter apps
  • API models
  • fromJson/toJson

Common Errors

  • Invalid JSON

Why Use Our JSON to Dart?

  • 100% client-side — your data never leaves your browser. No server processing, no data collection.
  • No sign-up required — start using the tool instantly with no registration or installation.
  • Keyboard shortcuts — press Ctrl+Enter to run, ? for shortcuts list, Ctrl+B to toggle sidebar.
  • Persistent state — your input is automatically saved across sessions using local storage.
  • IDE-style interface — Monaco Editor (the engine behind VS Code) with syntax highlighting and error detection.
  • Multi-format conversion — convert between JSON, XML, CSV, and YAML without switching tools.

Frequently Asked Questions

What does JSON to Dart output?

It generates a Dart class with final fields and a constructor.

Does it generate fromJson?

The tool outputs the class structure. You can add fromJson/toJson manually or with code generation.

Is my data sent to a server?

No. Conversion runs in your browser.

Is it free?

Yes. Free, no sign-up.

Try JSON to Dart Now

Paste your data into the editor above for instant processing. Use Ctrl+Enter anytime to re-run quickly.

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