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## Steps to upgrade

Follow the steps below to upgrade your Optimizely project to the latest MVC version.

  1. Upgrade your site to the latest NuGet package for [ASP.NET MVC](🔗), run "Update-Package Microsoft.AspNet.Mvc" in the Package Manager Console.

  2. Update the application **web.config** file in your project as follows: \- Change the **System.Web.Mvc** version number from "4.0.0.0" to "5.0.0.0".  \- Change the **System.Web.Helpers** and **System.Web.WebPages** version number from "2.0.0.0" to "3.0.0.0" (if not already done). If **System.Web.WebPages.Razor** exist as a dependent assembly it should also have version "3.0.0.0". \- Change the **webpages:Version** in the **<appSettings>** section from 2.0.0.0.0 to 3.0.0.0. The result should look like:


  1. Update the **web.config** file in the **Views** folder as follows: \- Update elements containing **System.Web.Mvc** from version "4.0.0.0" to "5.0.0.0". \- Update elements containing **System.Web.WebPages.Razor** from version "2.0.0.0" to "3.0.0.0". 




  1. If you use Web API 1, run "Install-Package Microsoft.AspNet.WebApi.WebHost" in the Package Manager Console to update your global.asax from:

    

    to:

    
  2. Build your solution and verify that the site is working.

## See also

  • [How to upgrade an ASP.NET MVC 4 and Web API Project to ASP.NET MVC 5 and Web API 2](🔗) (Microsoft)