C# What is difference between Path and PathString

What is difference between Path and PathString class?

In C#, Path and PathString are completely different types and are used in different contexts.

Feature	Path	PathString
Namespace	System.IO	Microsoft.AspNetCore.Http
Type	static class	struct
Purpose	Work with file system paths	Work with HTTP URL paths
Used in	Desktop apps, console apps, file handling	ASP.NET Core web apps
Represents	File/folder paths	URL request path
Example	C:\Docs\file.txt	/products/details

1. Path → File and directory path utilities

System.IO.Path contains static methods to manipulate filesystem paths.

Example:

string full = @"C:\Docs\report.pdf";
Console.WriteLine(Path.GetFileName(full));       // report.pdf
Console.WriteLine(Path.GetExtension(full));      // .pdf
Console.WriteLine(Path.GetDirectoryName(full));  // C:\Docs
Console.WriteLine(Path.Combine("C:\\Docs", "a.txt"));

Common methods:

• Path.Combine()
• Path.GetFileName()
• Path.GetExtension()
• Path.GetDirectoryName()
• Path.ChangeExtension()
• Path.GetTempPath()

Path itself does not store a path.

2. PathString → URL path wrapper for ASP.NET Core

PathString represents the path part of an HTTP request URL.

Example URL:

https://example.com/products/123?sort=asc

Parts:

• Scheme: https
• Host: example.com
• Path: /products/123   ← PathString
• Query: ?sort=asc

Example:

app.Use(async (context, next) =>
{
    PathString path = context.Request.Path;
 
    if (path.StartsWithSegments("/api"))
    {
        Console.WriteLine("API request");
    }
 
    await next();
});

Useful methods:

• StartsWithSegments()
• Add()
• FromUriComponent()
• ToUriComponent()

Example:

PathString p1 = "/users";

PathString p2 = "/123";
Console.WriteLine(p1.Add(p2));// /users/123

One important difference

Path.Combine() automatically uses OS separators:

Path.Combine("docs", "file.txt")
// Windows → docs\file.txt
// Linux → docs/file.txt

PathString always uses URL style:

new PathString("/docs/file.txt")

So:

• Use Path → when dealing with files and folders
• Use PathString → when dealing with web request URLs