Free TOML to C# Converter — generate C# classes from TOML in your browser

🧬 TOML to C# — Free Online Tool

Convert TOML to C# online, free. TOML is a readable configuration format built around key/value pairs and tables. C# classes model data for .NET with System.Text.Json support. TOML to C# conversion parses your TOML against the TOML v1.0.0 grammar (https://toml.io/en/v1.0.0), builds an in-memory model of its keys, nested objects and arrays, then emits ready-to-use C# types with System.Text.Json attributes following the C# language reference conventions. Processing runs in your browser in JavaScript with no upload or server round-trip — no size limit beyond your device's memory, so multi-megabyte documents convert in milliseconds and sensitive payloads never leave your machine. Typical uses include .NET APIs, desktop apps and Azure functions.

🚀 Why use this TOML to C# tool?

It maps the full structure of your TOML onto idiomatic C# types, following the C# language reference conventions. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.

Key Features

Instant, in-browser

Paste TOML and generate C# types from C# immediately. Conversion runs client-side, so there is no upload wait and large documents stay fast.

🧩Structure-aware mapping

Nested TOML objects, tables and arrays are mapped faithfully onto C#, including nested types and optional fields.

🔒100% private

Your TOML never leaves your device — everything is processed locally in JavaScript, with nothing logged or stored.

🆓Free, no signup

Unlimited conversions with no account, no quotas, and no watermark. Works on desktop and mobile.

Popular Use Cases

Typed models from samples

  • Turn a sample TOML payload into C# types
  • Skip hand-writing boilerplate models
  • Keep front-end and back-end shapes in sync

.NET APIs

  • .NET APIs
  • desktop apps
  • Azure functions

Onboarding a new API

  • Paste an example TOML response
  • Get typed C# to consume it safely
  • Catch shape mismatches at compile time

What It Handles

Structure

  • Nested objects & tables
  • Arrays / lists
  • Deeply nested documents

Values

  • Inferred types (string, number, boolean)
  • Optional / nullable fields
  • Nested type names

Workflow

  • Copy or download output
  • Load an example to try it
  • Validate & format the input

Worked example

A TOML document and its C# equivalent:

TOML input:

host = "db.internal"
port = 5432
secure = true

Output:

public class Server
{
    public string Host { get; set; }
    public int Port { get; set; }
    public bool Secure { get; set; }
}

Sources & References

Frequently Asked Questions

How do I convert TOML to C#?

Paste your TOML into the editor and press "Convert to C#". The tool parses it against the TOML v1.0.0 grammar, then generates C# types following C# language reference conventions — instantly and entirely in your browser. You can validate or format the TOML first to be sure it is clean.

How is TOML structure represented in C#?

TOML values are typed and it has first-class dates and times, so they carry into C# cleanly. TOML tables become nested C# types, and arrays-of-tables become lists.

Are optional fields detected when generating C#?

Optional or nullable members in the generated C# are inferred from keys missing in some records of your TOML, following C# language reference. Include the optional fields in your sample so they are typed correctly.

What is the difference between TOML and C#?

TOML (Tom's Obvious Minimal Language) (TOML) — TOML is a readable configuration format built around key/value pairs and tables. C# classes (C#) — C# classes model data for .NET with System.Text.Json support. This converter maps the structure of your TOML onto C# so you can use it for .NET APIs.

Does the converter validate my TOML first?

Yes. Invalid TOML is flagged with a clear error before anything is converted. Common TOML problems to check are correct key/value pairs, quoted strings, and valid [table] headers. Starting from clean input keeps the generated C# accurate.

Is my TOML data private?

Yes. The entire TOML-to-C# conversion runs locally in your browser in JavaScript — your TOML is never uploaded, logged or stored. That matters when the data is something like Rust Cargo & Python pyproject config, which should not leave your machine.

Where can I use the C# output?

The generated C# is ready for .NET APIs, desktop apps and Azure functions. Copy or download it and drop it straight into your codebase.

🎓 Pro Tips

  • Tip 1: Validate or format your TOML first (the Validate / Format buttons) so the converter works from clean, TOML v1.0.0-conformant input.
  • Tip 2: Give the tool a representative TOML sample — optional fields are only detected from the keys actually present, so include them if they matter.
  • Tip 3: Authoritative reference for the input format: TOML v1.0.0 — https://toml.io/en/v1.0.0.
  • Tip 4: For the output, follow the C# language reference (https://learn.microsoft.com/dotnet/csharp/) conventions in your codebase.