Setting Up Your License Key File
Telerik UI for ASP.NET Core requires activation through a license key for both trial and commercial licenses. This article describes how to download your personal license key and use it to activate the UI for ASP.NET Core components.
Starting with Telerik UI for ASP.NET Core 2025 Q1 release, you must activate the UI components by providing a license key file. Previous versions require a script key instead of a license key file.
Basics
To install a license key, you must have a developer or trial license for:
- Telerik UI for ASP.NET Core
- Any product bundle that includes Telerik UI for ASP.NET Core, such as DevCraft.
If you are new to Telerik UI for ASP.NET Core, sign up for a free trial.
The Telerik.UI.for.AspNet.Core NuGet package depends on the Telerik.Licensing NuGet package. During project build, the Telerik.Licensing package automatically verifies the license key and activates Telerik UI for ASP.NET Core in that project.
Follow the steps below for automatic or manual license key installation in your local development environment. To build UI for ASP.NET Core apps in a CI/CD environment, set up a Telerik license key in CI/CD.
The Telerik UI NuGet package (therefore, the Kendo.Mvc.dll that comes with the package) must be the same version as the Kendo UI script files referenced in the project's Layout file.
An invalid or missing license key results in app build warnings and watermarks in the application UI.
The license key file is personal and confidential. Do not commit this file to source control and do not save it to a publicly accessible location!
Automatic Installation
To download and install your Telerik license key automatically, use either of the following Telerik productivity tools:
- Telerik Control Panel—this tool downloads and installs different Telerik products on your machine.
- Telerik UI for ASP.NET Core Visual Studio extension—this tool adds or upgrades Telerik UI for ASP.NET Core in new or existing apps.
The above tools download and install a license key for you and make it available for all projects that you develop on your local machine. The license key file and location is specified in the Manual Installation section below.
Update your license key whenever you renew or purchase a new Telerik license.
Manual Installation
To download and install your Telerik license key:
- Go to the License Keys page in your Telerik account.
- Click the Download License Key button.
- Save the
telerik-license.txtfile to:- (on Windows)
%AppData%\Telerik\telerik-license.txt, for example,C:\Users\...\AppData\Roaming\Telerik\telerik-license.txt - (on Mac or Linux)
~/.telerik/telerik-license.txt, for example,/Users/.../.telerik/telerik-license.txt
- (on Windows)
This will make the license key available to all Telerik .NET apps that you develop on your local machine.
If you need to activate Telerik UI for ASP.NET Core only in a specific app, then save telerik-license.txt to the root folder of your project or solution.
Update your license key whenever you renew or purchase a new Telerik license.
By default, when you have an active license, the required Kendo UI scripts are activated internally. Version 2025.1.227 introduces the ActivateKendoScripts method that you can use to activate the Kendo UI scripts manually. Call this method if no HtmlHelper or TagHelper components are used on the View.
@(Html.Kendo().ActivateKendoScripts())License Key Updates
Always install a new license key whenever you:
- renew or purchase a new Telerik license
- Start a new trial
The new license key includes information about all previous purchases. The download and installation of a new license key is referred to as a license key update.
- If you used automatic license key installation, then open the tool that you used to download and install the license key file. You can also update the license key file by using the manual steps above.
- If you used the manual license key installation, then repeat the same manual steps.
- To update your license key in CI/CD environments, get your new license key and update the environment variable value.