Free Online JSON to C# Class Generator

Direct Answer FreeDailyTools JSON to C# Generator converts raw JSON payloads into idiomatic C# 14 classes or records directly in your browser. Execution runs 100% locally with zero server transmissions, protecting proprietary API models. Supports System.Text.Json attributes, nullable reference types, PascalCase formatting, and nested model inference.

1. Paste JSON Payload: Paste your sample JSON payload or API response into the editor.
2. Configure Generation Options: Choose C# Records vs Classes, System.Text.Json vs Newtonsoft attributes, and Root class name.
3. Generate C# Models: Click 'Generate C# Code' to produce clean, typed C# models with inferred types.
4. Copy or Download: Copy the code directly to your clipboard or download as a .cs file for your .NET solution.

Operational Limits & Specifications

The tool parses the JSON AST (Abstract Syntax Tree), inspects type primitives, and traverses object graphs. It computes schema unions for arrays of objects, normalizes identifier names to valid C# keywords, and emits formatted C# syntax.

Many online C# generators only produce old C# 5 mutable classes with public getters and setters. FreeDailyTools emits modern C# 14 records with init properties and nullable annotations.

• Provide a comprehensive sample JSON payload that includes optional fields so nullability is accurately inferred.
• Use 'Records' for immutable DTOs and API response models in modern .NET applications.
• Check 'Use PascalCase' to ensure your C# properties follow standard Microsoft C# naming conventions.
• If your JSON contains date strings, the generator maps them to DateTime or DateTimeOffset.

Are my confidential API payloads sent to any server?

No. The entire code generation engine executes client-side in your browser. Secret tokens and proprietary schema structures remain confidential.

Does the generator support modern C# 14 record types?

Yes. You can toggle between modern positional records, init-only records, or traditional mutable classes.

Does it support System.Text.Json serialization attributes?

Yes. It adds [JsonPropertyName("original_key")] and preserves PascalCase naming conventions.

How are nested JSON objects and arrays handled?

Nested objects are automatically extracted into separate strongly-typed C# classes, and arrays are typed as List<T> or IReadOnlyList<T>.

Does it handle nullable reference types?

Yes. When enabled, properties are declared with C# nullable annotations (e.g. string?, int?).

Can I generate code for arrays of objects at the root?

Yes. If the root payload is a JSON array, the tool inspects items to synthesize a unified C# model.

Last reviewed: October 28, 2026 Learn about our architecture in How we process your files and mathematical Methodology.