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Why upgrade to CMS 12?

Describes why upgrading to Optimizely Content Management System (CMS 12) is advantageous to you.

Optimizely Content Management System (CMS 11) is built on ASP.NET 4. It is an "everything-in-a-box" type of product, and it is simple, easy to use, and familiar to users.

CMS 12 is built on ASP.NET Core, which has a lot of differences from ASP.NET 4, but fundamentally it is still the same product - everything-in-a-box, simple, easy to use, and familiar.

Unlike the underlying framework where the APIs were migrated from ASP .NET 4 to ASP.NET Core, CMS 12 and CMS 11 have a one-to-one behavior and syntax using the same architectural patterns. You can still build everything in one application as a developer. Nothing changes in how your website looks, how it is structured, or how the editors work.

Why upgrade from ASP.NET 4 to ASP.NET Core?

  • Microsoft is no longer investing in the ASP.NET 4 stack.
  • ASP.NET Core performance is impressively fast compared to ASP.NET 4.
  • Ecosystem - ASP.NET Core is a popular framework for server-side programming, APIs, and integrations. Partners want this, and with CMS 12 and Commerce 14, they are getting it.


CMS 12 supports more headless-style deployments.

REST APIs were built because some developers do not want to work with ASP.NET development. For example, JavaScript developers may want to build things in JavaScript frameworks, such as React. Or maybe, they are running their websites on Node JS and do not benefit from using the ASP.NET framework.

REST APIs assume that the logic and control are handled outside of Optimizely. Using the Optimizely headless solutions, you can build solutions regardless of your chosen framework–you can use ASP.NET Core or JavaScript frameworks.

Versions of CMS 12

CMS 12 comes in the following versions:

  • CMS 12 – The core platform built on ASP.NET Core.
  • CMS 12 REST APIs – The headless solution where you can use .ASP.NET Core or JavaScript frameworks. Planned supporting APIs are:
    • ASP.NET SDK for headless implementations.
    • React SDK for implementations using React.
    • Vue.js SDK for implementations using Vue.js.