How do I compare two C# files?

Paste or upload both versions and click Compare. Changed lines are highlighted with token-level marks, and you can merge the versions afterwards.

What is a .cs file and how do I open it?

A .cs file is plain-text C# source code. Any text editor opens it — including this page: drop the file onto a panel to read or compare it.

How do I compare strings in C# code?

Use string.Equals for content equality, passing a StringComparison value when case or culture rules matter, and string.Compare for ordering. The == operator works for strings but hides intent in APIs that accept objects.

The files came from different formatters — everything shows as changed.

Enable ignore-whitespace to neutralize indentation and spacing differences, or run both files through dotnet-format with the same settings before comparing.

Can I compare generated or decompiled code?

Yes — paste both sides as text. Ignore-whitespace plus word granularity keeps generated-code churn readable.

Is my code uploaded anywhere?

No. The comparison runs entirely in your browser — safe for proprietary source.

Your code never leaves your browser

Compare Two C# Files Online

Paste two versions of a C# class and see every change highlighted — edited methods, new attributes, changed LINQ chains — instantly.

Original text

0 lines · 0 characters

Changed text

0 lines · 0 characters

Paste or drop text into both boxes, then press Compare.

Everything runs in your browser — nothing is uploaded.

How to compare two C# files

1
Add both versions
Paste the code or drop .cs files onto the panels — classes, records, partial classes or whole source files.
2
Cut through formatting noise
Enable ignore-whitespace when the versions come from different formatter settings; use word granularity to see token-level edits.
3
Review & merge
Walk the highlighted changes, merge the versions git-style if you are consolidating, and export the result.

C# Compare showing an example comparison result with differences highlighted

See what really changed between two C# files

Whether it is a .cs file from a colleague, generated code from two builds, or a snippet you are aligning with production, this diff shows exactly what changed: lines are aligned like a code review, and word-level highlighting marks the changed tokens inside long LINQ chains, generic signatures and attribute lists.

Formatting differences between Visual Studio, Rider and dotnet-format are neutralized with the ignore-whitespace option, so the diff concentrates on logic: a changed null-check, a new async modifier, an edited property initializer.

Typical uses: comparing scaffolded or T4-generated code between runs, reviewing a decompiled assembly against source, checking what a NuGet update changed in generated clients, or diffing two versions of a configuration or Razor file.

Two quick answers for common searches: a .cs file is a plain-text C# source file — you can open it in any editor, including this page. And to compare strings in C# code, use string.Equals (optionally with StringComparison for case or culture rules) rather than the == operator when intent matters; use string.Compare for ordering.

FAQ

C# comparison — frequently asked questions

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How to compare two C# files

Add both versions

Paste the code or drop .cs files onto the panels — classes, records, partial classes or whole source files.

Cut through formatting noise

Enable ignore-whitespace when the versions come from different formatter settings; use word granularity to see token-level edits.

Review & merge

Walk the highlighted changes, merge the versions git-style if you are consolidating, and export the result.

See what really changed between two C# files