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Differences Between Cookies and Sessions in ASP.NET Core MVC

In this article, I will discuss the Differences Between Cookies and Sessions in ASP.NET Core MVC Applications with Examples. Please read our previous article discussing In-Memory or In-Proc vs Distributed or Out-Proc Sessions in ASP.NET Core MVC Application.

Differences Between Cookies and Sessions in ASP.NET Core MVC

Cookies and Sessions are mechanisms for State Management in ASP.NET Core MVC Applications, but they have distinct differences in where data is stored, how long it persists, and how it’s accessed. Here’s a comparison of cookies and sessions in the ASP.NET Core MVC Web Application:

 Storage Location

• Cookies: Stored on the client’s browser. When a cookie is created, it is sent to the client’s browser along with the HTTP response. The browser then sends it back with every subsequent request to the server.
• Sessions: Stored on the server. Session data is kept on the server, and a unique identifier, usually a session ID, is sent to the client’s browser and stored inside a cookie called a session cookie.

 Lifespan

• Cookies: Can be persistent or session-based. Persistent cookies remain on the client’s device for a set period or until manually deleted, which can be specified in the cookie’s expiration attribute. Session cookies expire when the browser session ends.
• Sessions: Typically, they expire when the user closes the browser or after a period of inactivity, which can be configured in ASP.NET Core MVC.

 Security

• Cookies: Because they are stored on the client side, cookies are more susceptible to security threats like cross-site scripting (XSS) and cross-site request forgery (CSRF). Sensitive data stored in cookies should be encrypted and/or flagged with security settings like HttpOnly and Secure.
• Sessions: Considered more secure than cookies as the data is stored on the server. Only the session ID is passed back and forth between client and server, reducing the exposure of sensitive data.

 Data Capacity

• Cookies: It is suitable for storing small amounts of data because each HTTP request includes cookies, adding overhead to the request. The size of cookies is also limited (about 4KB per cookie).
  
• Sessions: It is more suitable for storing larger amounts of data. As only the session ID is exchanged in each HTTP request, this method can handle larger data volumes without significantly impacting the request size.

 Use Cases

• Cookies: Cookies are commonly used to store user preferences, authentication tokens, and other small pieces of data that need to persist across requests.
• Sessions: Ideal for sensitive data that shouldn’t persist on the client’s machine, like shopping cart contents or current user state in multi-page forms.

Accessibility:

• Cookies: Cookies are accessible on both the client side (JavaScript) and server-side (ASP.NET Core), making them useful for storing data that needs to be available to both the client and server.
• Session: Session data is only accessible on the server side. This makes sessions more secure for storing sensitive information, as the data is not exposed to the client.

Considerations for Choosing

• Data Sensitivity: Use sessions for sensitive data to avoid client-side tampering.
• Data Size: For large data, prefer sessions. Cookies are suitable for small bits of data.
• Persistence Need: If you need data to persist beyond a user session, cookies are a better option.
• Performance Impact: Cookies are sent with every HTTP request, which can impact performance, especially when dealing with large cookies or many small cookies.

 In the next article, I will explain Filters in ASP.NET Core MVC with Examples. In this article, I try to explain the Differences Between Cookies and Sessions in ASP.NET Core MVC with Examples. I hope you enjoy this Differences Between Cookies and Sessions in ASP.NET Core MVC article.