C# ↔ VB.NET Converter

Convert a code snippet between C# and VB.NET. VB.NET to C# is the default direction — it's the higher-quality conversion and the more common real-world migration path.

By Pankaj Kumar · DevToolsHub · Last updated Jul 2026

What this tool does

Paste a C# or VB.NET code snippet and get a compiler-grade translation to the other language. Unlike this site's other .NET-category tools, this one is not a hand-written parser — converting between two full programming languages correctly requires an actual compiler front end, so this tool sends your snippet to the DevToolsHub API, which runs it through ICSharpCode.CodeConverter (the open-source, Roslyn-based converter also used by the official CodeConverter web tool and Visual Studio extension), licensed under MIT.

Why VB.NET → C# is the default direction

The underlying library's own maintainers are explicit about this: VB.NET-to-C# conversion quality is substantially higher than the reverse. C#-to-VB.NET conversion is documented as intended for "incorporating snippets from Stack Overflow into an existing VB codebase, or helping learn one language from the other" — not for production-grade whole-codebase migration. VB.NET → C# is also the far more common real-world migration path (moving a legacy VB.NET codebase to C#), so it's the direction selected by default.

What converts cleanly vs. what needs review

Converts cleanlyUsually needs review
Properties, fields, constructors, classes, ModulesLate binding (any variable typed Object under Option Strict Off)
Loops (For, For Each, While, Do)My namespace members (My.Computer, My.Settings, My.Forms — VB-only, no direct C# equivalent)
LINQ query syntax, async/await, string interpolationXML literals (a VB-only language feature)
GenericsModern C# pattern matching / switch expressions when converting C# → VB.NET — verified directly: this is where C# → VB.NET conversion is weakest, sometimes producing unusable output rather than just a flagged gap
Standard control flow (If/Select Case), With/End With blocksAny other very recent C# syntax when converting C# → VB.NET (VB.NET "has fewer features, tools and developers" per the library's own README)

That C# → VB.NET pattern-matching gap is worth calling out specifically, since it's not a small cosmetic miss: converting a C# switch expression with type patterns produced VB.NET output missing large structural pieces (not just a flagged unconverted line) in direct testing. The Review needed list will still show you every place this happened — but treat a C# → VB.NET conversion involving pattern matching as a rewrite starting point, not a near-complete translation.

When the converter can't translate a construct cleanly, it doesn't fail silently — it embeds a comment (or, for a fully broken statement, a #error directive) directly in the output describing what it couldn't convert and why. This tool pulls every one of those into the Review needed list above the output, so you see them immediately instead of finding them buried in the code later. A successful-looking conversion can still contain one or more of these — always check the list, not just whether the output "looks like real code."

Input size limit

This tool converts individual snippets, not whole projects — input is capped at 100,000 characters. For a full VB.NET-to-C# project migration, the command-line tool or Visual Studio extension (same underlying converter) can operate on entire solutions with full project context, which this single-snippet tool intentionally doesn't attempt.

How to use this tool

  1. Pick a direction — VB.NET → C# (default) or C# → VB.NET.
  2. Paste your code snippet.
  3. Click Convert. The first conversion after a deploy is slower while the compiler initializes; subsequent conversions are fast.
  4. Check the Review needed list (if it appears) before using the output — it flags exactly what the converter couldn't translate automatically.

FAQ

How do I convert VB.NET to C# online?

Paste your VB.NET code into the input editor (the default direction), click Convert, and review any items in the "Review needed" list before using the output.

Which direction is more reliable?

VB.NET to C# — it's the default for that reason. The underlying library's own maintainers document C# to VB.NET as intended for incorporating snippets or learning one language from the other, not for production-grade migration; expect more items in the Review needed list going that direction.

Is my code sent to a server?

Yes — conversion runs server-side: your code is sent over HTTPS to the DevToolsHub API, converted using Roslyn, and the result returned. This can't run client-side in the browser the way most of this site's other .NET tools do, since it needs a real compiler. The raw code text is not written to any log; only the operation type and a success/failure status are recorded for monitoring, retained for 24 hours.

What does the "Review needed" list mean?

The converter embeds a comment or #error directive in the output anywhere it couldn't translate a construct automatically — a late-bound call, an XML literal, a With block, and similar VB-only or edge-case constructs. This tool extracts every one of those into a visible list above the output so you don't have to scan the whole snippet by eye. A conversion can report success and still have items here — always check the list.

Is there a size limit?

Yes — 100,000 characters. This tool is built for snippets, not whole files or projects. For a full solution migration, the same underlying library is available as a command-line tool and Visual Studio extension with full project context.

What library powers this converter?

ICSharpCode.CodeConverter, an open-source, MIT-licensed, Roslyn-based converter — the same one behind the official CodeConverter web tool and Visual Studio extension. DevToolsHub isn't affiliated with that project; this page just calls the library server-side.

Why isn't this tool purely client-side like most others on this site?

Language conversion needs a real compiler front end (Roslyn) to parse and re-emit code correctly — that's a large, server-oriented dependency that doesn't belong in a page running in your browser session. Every other .NET-category tool on this site avoids exactly this kind of dependency; this converter is the deliberate exception, because a hand-written parser cannot produce compiler-grade language conversion and wrong output is unacceptable for a converter.

Related Tools

This tool is built with ASP.NET Core 8, Blazor Server, and ICSharpCode.CodeConverter (MIT-licensed, Roslyn-based) — the deliberate exception to this table's usual "no Roslyn/compiler dependency" pattern, isolated to the API service. It runs securely on Microsoft Azure.
Input Section

VB.NET input

Public Class Person
    Public Property Name As String
    Public Property Age As Integer

    Public Function Greet() As String
        Return "Hello, " & Name
    End Function
End Class
Output Section

Generated C#

C# output

✉

Feedback or suggestions?

Found a bug or have an idea for a new tool? Drop me an email.

[email protected]
☕

Find the tools useful?

Everything here is free. If it saves you time, a coffee keeps it running.

Buy me a coffee
About · Privacy · Terms · Editorial Policy · Client-side & server-processed tools · No personal data retained server-side · © 2026 DevToolsHub