Loading…

About Online C# Formatter

Paste your C# code (or drop a file) and click "Format". This tool applies CSharpier’s canonical style for consistent diffs and friction-free code reviews. It understands modern C# features like records, pattern matching, raw string literals, file-scoped namespaces, and more — so what you test here behaves like a real-world .NET project.

Why Developers Use This C# Formatter

  • Canonical, opinionated style via CSharpier for stable and predictable diffs across your whole team
  • Normalizes whitespace, indentation, line breaks, and brace layout without touching the logic of your code
  • Supports modern C# syntax (records, pattern matching, raw strings, top-level statements, file-scoped namespaces, and more)
  • Easy copy and download of formatted C# code from the output panel — perfect for quick one-off fixes
  • Ideal for code reviews, refactors, katas, and cleaning up legacy .cs files before migrating to .NET 6/7/8
  • Plays nicely with linters and analyzers — let CSharpier handle layout, and let analyzers handle rules and style
  • Designed for short-lived formatting — avoid pasting highly sensitive or secret code; use the CSharpier CLI for confidential projects

🔧 How to Format C# Code (Step-by-Step) for csharp-formatter

1

1. Paste or Drop Your C# Code

📥 Paste your C# code into the input editor, or drop a .cs file onto the dropzone. The formatter expects syntactically valid C# — anything you could compile in a typical .NET project.

2

2. Run the Formatter

⚙️ Click the "Format" button to apply CSharpier’s canonical layout. Indentation, braces, and line breaks are normalized while preserving behavior. For large snippets, this also makes deeply nested logic or LINQ pipelines much easier to read.

3

3. Review, Copy, or Download

🔍 Compare the original and formatted code. Once you are satisfied, copy the result back into your editor or download the formatted .cs file. Use it as a quick pre-commit cleanup or as a reference for your team’s style.

Technical Details & Style Notes

Formatting Engine & Style

This formatter uses CSharpier to apply a canonical, opinionated layout to your C# source. It focuses purely on formatting and does not change program behavior.

AspectWhat It DoesNotes
ParsingParses C# syntax and rewrites the code layoutNo semantic or behavioral changes; it only reshapes the source.
IndentationNormalizes indentation to a consistent style4-space indentation is common in C# projects and is used by many teams.
Braces & BlocksApplies a consistent brace and newline styleImproves readability and makes diffs smaller and easier to review.
WhitespaceCleans up extra spaces and normalizes blank linesHelps highlight real changes instead of formatting noise in reviews.
Long LinesWraps long expressions according to CSharpier rulesReduces horizontal scrolling and keeps code visually scannable.
This tool focuses on layout and whitespace. It does not rename symbols, refactor code, reorder usings, or apply analyzers.

Supported Input & Limits

The formatter is designed for typical C# files used in .NET applications, libraries, APIs, and game projects.

ParameterLimit / BehaviorNotes
File extensions.csBest for standard C# source files, including Unity scripts and ASP.NET controllers.
MIME typestext/x-csharpUsed to detect C# input in the editor and configure syntax highlighting.
Max input size≈ 2 MB of source codeVery large solutions are better handled via the CSharpier CLI or editor integration.
EncodingUTF-8 recommendedConvert legacy encodings (e.g., Windows-1252) before formatting for best results.

Example: Before and After

Here is a small example showing how messy C# code is normalized into a clean, review-ready layout.

// Before
using System;using System.Collections.Generic;namespace App{class Z{public static int Sum(List<int> xs){int s=0;foreach(var x in xs){s+=x;}Console.WriteLine($"Sum={s}");return s;}}}

// After
using System;
using System.Collections.Generic;

namespace App
{
    class Z
    {
        public static int Sum(List<int> xs)
        {
            int s = 0;
            foreach (var x in xs)
            {
                s += x;
            }

            Console.WriteLine($"Sum={s}");
            return s;
        }
    }
}

Command-Line & Editor Integrations

If you want the same formatting style in your local workflow or CI pipeline, install CSharpier as a .NET tool and integrate it into your build, editor, or pre-commit hooks.

All Platforms (.NET tool)

Install CSharpier globally

dotnet tool install -g csharpier

Adds the `csharpier` CLI to your PATH so you can run it from any project.

Format all C# files in a repo

csharpier **/*.cs

Recursively formats every .cs file under the current directory.

CI check without changing files

csharpier --check **/*.cs

Exits with a non-zero status if files are not properly formatted, ideal for pull request gates.

Editor Integrations

Visual Studio, VS Code, Rider

Install the CSharpier extension or configure it as an external tool, then enable "Format on Save".

Keeps your codebase consistently formatted without manual steps.

Add a repo-local tool manifest with `dotnet new tool-manifest` and `dotnet tool install csharpier` so every contributor uses the same CSharpier version.

Popular Use Cases for the C# Formatter

Team-Wide Consistency

Enforce a single, canonical style across your .NET codebase and keep diffs small.

  • Apply the same formatting to all .cs files in shared repositories.
  • Run CSharpier in CI to block unformatted changes on pull requests.
  • Reduce noise in code reviews by avoiding style-only discussions.

Rapid Refactors

After large edits or refactors, re-format to restore readability and structure.

  • Normalize indentation after moving or duplicating blocks of code.
  • Make long LINQ queries and interpolated strings easier to read.
  • Clean up stray spaces, inconsistent braces, and awkward breaks.

Unity & Game Development

Keep gameplay scripts and engine integrations tidy in big Unity projects.

  • Consistent braces and layout across hundreds of small scripts.
  • Easier code reviews in large mono-repos and multi-team projects.
  • Combine with analyzers to keep performance-critical code clean and safe.

ASP.NET Core, APIs & Blazor

Make controllers, services, Razor components, and DTOs easier to read and maintain.

  • Predictable layout for attributes, records, and minimal APIs.
  • Cleaner diffs when changing endpoints, contracts or DTO shapes.
  • Onboard new team members faster with a single, trusted style.

❓ Frequently Asked Questions

🆚Formatter vs linter — what’s the difference?

A formatter rewrites the layout of your code (spaces, newlines, indentation, braces). A linter analyzes your code for potential problems, style issues, or best-practice violations. Many teams use both: the formatter for structure, the linter for guidance and diagnostics.

🔒Does formatting change how my C# code behaves?

No. CSharpier focuses on formatting and layout only. It is designed to preserve the semantics of your code while changing whitespace, indentation, and line breaks.

🧩Does this tool reorder usings or optimize imports?

No. This formatter does not reorder using directives or refactor code. Use IDE features or tools like `dotnet format` if you need import reordering, code cleanup, or additional analyzers.

📦Does it support modern C# features?

Yes. CSharpier is built with modern C# in mind and supports features such as records, file-scoped namespaces, pattern matching, top-level statements, raw string literals, and more.

🏗️How do I enforce this formatting style in CI?

Install CSharpier in your CI environment and run `csharpier --check **/*.cs`. If the command exits with a non-zero status, you can fail the build and prevent unformatted code from being merged.

🔐Is it safe to paste proprietary or confidential C# code here?

This tool is designed for short-lived formatting of pasted code, but as a general rule you should avoid uploading highly sensitive or secret business logic to any online service. For confidential projects, prefer running CSharpier locally or in a self-hosted CI environment.

Pro Tips

Performance Tip

Commit a repo-local tool manifest so your whole team uses the exact same CSharpier version and avoids "works on my machine" diffs.

Best Practice

Add an `.editorconfig` with your preferred line width and style settings to keep C# formatting consistent across IDEs, contributors, and CI.

Performance Tip

Use a Git pre-commit hook or tools like pre-commit/Husky to auto-format staged `.cs` files before every commit.

Best Practice

Combine this formatter with Roslyn analyzers or other linters so you get both clean layout and actionable diagnostics.

Additional Resources

Other Tools