Type Name:

JSON Input

F# Output

What is JSON to F# Converter?

Need to generate F# types from your JSON (JavaScript Object Notation) data? This tool does that instantly. Perfect for F# developers building .NET applications, web services, or data-driven systems who need type-safe JSON deserialization. Generate F# records, discriminated unions, and type definitions automatically.

According to the F# documentation, records are perfect for representing JSON data structures. Our converter analyzes your JSON and generates idiomatic F# code with proper types. First, validate your JSON using our JSON Validator, then convert it to F#. You can also format your JSON with our JSON Formatter first if needed.

Everything happens in your browser – your JSON never leaves your computer. Convert, download, and use your F# code right away.

How to Use JSON to F#

Follow these steps to convert JSON to F# types. Each step uses the actual buttons and panels on this page.

Paste, Upload, or Load Sample

Paste your JSON into the left JSON Input panel, or click Upload to load a .json or .txt file. Click Sample to see example JSON. Example input:

{"subscriberId":"SUB-1001","plan":"Unlimited 5G","dataUsage":45.2,"status":"active"}

Invalid JSON will show an error. Use our JSON Validator first if unsure. Configure type name in the options above.

View Generated F# Output

The right F# Output panel shows the generated F# types instantly. JSON objects become records, nested objects become nested types.

Download or Copy

Click Download to save the F# file, or Copy to copy to your clipboard. Use Clear on the input panel to start over. All processing runs in your browser.

When You'd Actually Use This

Web API Development

Generate F# types from JSON API responses for web services. Create domain models for REST APIs or microservices. Perfect for ASP.NET Core, Giraffe, or Suave web frameworks.

Data Processing

Convert JSON data files to F# record types for data analysis and processing. Perfect for ETL pipelines, data transformation, and functional data processing workflows.

.NET Application Development

Generate F# types from JSON schemas for applications. Create strongly-typed data models for JSON configuration, API contracts, or domain models.

Type-Safe Integration

Generate F# types from JSON data for integrating with external APIs or data sources. Create compile-time checked data models for type-safe JSON handling.

Common Questions

Is my JSON data stored?

Nope. Everything happens right in your browser. Your JSON never leaves your computer – we don't even see it. Check out the ECMA-404 standard for more details.

How are JSON objects handled?

JSON objects become F# records. Properties become record fields, and nested objects become nested records or references. Arrays become F# lists or arrays. Check out the RFC 8259 for more details.

Can I use the generated F# code?

Yes. The generated F# code is valid and ready to use. Drop it into your F# project and start using it. You may want to review and refine the types for your specific use case.

What about JSON serialization?

The generated F# records work with System.Text.Json or Newtonsoft.Json for JSON serialization. You may need to add serialization attributes for custom property names.

Does it work with large JSON files?

Yep. Since everything happens in your browser, it depends on your device. Small to medium JSON structures convert instantly. Really huge structures might take a few seconds.

What F# version is supported?

The generated code works with F# 4.0 and later. It uses standard F# features and follows F# conventions for maximum compatibility.

Other JSON Tools You Might Need

Conversion is just one JSON task. Here are other tools that work well together:

JSON to F# Converter