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Frequently Asked Questions

Updated on Jan 6, 2026

This article lists the answers to the most frequently asked questions (FAQs) about working with the Kendo UI for jQuery license key.

Does the license key expire?

Yes, the license key expires at the end of your support subscription:

For trial users, this is at the end of your 30-day trial.
For licensed developers, this is when your subscription expires.

You need to download and install a new license key after:

Starting a new trial
Buying a new license
Renewing an existing license
Upgrading an existing license

An expired perpetual license key is valid for all Kendo UI for jQuery versions which are published before its expiration date.

Will the product function with an expired license key?

This depends on your license:

Perpetual licenses will continue to function normally with an expired license key. However, the following will happen if you update or install a package version that is released after the expiration date of the license:
- A watermark will appear over selected Kendo UI for jQuery components.
- A licensing banner will pop over a page that uses unlicensed Kendo UI for jQuery components.
- A warning message will appear when calling the kendo-ui-license activate command.
- A warning message will appear in the browser console.
Subscription licenses will continue to function normally for deployed applications. However, the following will happen when you try to rebuild the application:
- A warning message will appear when calling the kendo-ui-license activate command.
Trial licenses will continue to function normally with an expired license key. The following will happen if you try to build or run the application:
- A watermark appears on application startup.
- A modal dialog appears on application startup.
- A warning message will appear when calling the kendo-ui-license activate command.
- A warning message similar to the following is logged in the build log.

See the Invalid License section for more information.

I updated the version of the Kendo UI for jQuery packages in my project and the invalid license errors have appeared. What is the cause for this behavior?

The most likely cause is that the newly installed Kendo UI for jQuery Components were released after the expiration date of your current license. To fix this issue:

If adding the license by using a script key:

Renew your Kendo UI for jQuery license, if necessary.
Download a new license script key.
Add the the license as a script reference.

If adding the license by using a license key (npm):

Renew your Kendo UI for jQuery license, if necessary.
Download a new license key file.
Activate the new license key.

Can I use the same license key in multiple builds?

You can use your personal license key in multiple pipelines, builds, and environments. However, each individual developer must use a unique personal license key.

Do I need an Internet connection to activate the license?

No, the license activation and validation are performed entirely offline.

Do I have to add the license key to source control?

No, you do not have to add the telerik-license.txt license key file or its contents to source control.

Build servers have to use the TELERIK_LICENSE environment variable as previously described.

Do not store the license key in plaintext, for example, in a GitHub Actions Workflow definition.

Is it possible to activate the license without executing commands?

Yes, if present, the license will be activated automatically during package installation. This applies to both the license key files and the environment variable. A diagnostic message will be printed in the npm install log.

Using the kendo-ui-license activate command is optional, but recommended in builds as it will return an error if the activation fails.

What happens if both the environment variable and the license key file are present?

If both the TELERIK_LICENSE environment variable and the telerik-license.txt file are present, then the environment variable will be used.

To enforce the use of the license key file, unset the environment variable.

My team has more than one licensed developer. Which key do we have to use?

To activate Kendo UI for jQuery you can use any of the keys associated with your subscriptions.

What happens if the developer who generated the license file leaves my company?

This doesn’t affect your license file. The license file is generated against a specific range of versions and it will be valid as long as the license code is valid for the product version you are using (that is, you need to change the license file only when you upgrade Kendo UI for jQuery).

Which versions of Kendo UI for jQuery require a license file?

Using any of the Kendo UI for jQuery components distributed through the following channels requires you to add valid license file to your application:

Distribution channel	Version
Kendo CDN (`kendo.cdn.telerik.com` and `cdn.kendostatic.com`)	version R3 2022 and later
npm packages (`@progress/kendo-ui`)	version R2 2022 and later
Trial installation bundle	version R3 2023 and later
`KendoUIProfessional.Trial` NuGet package	version R3 2023 and later

Are earlier versions of Kendo UI for jQuery affected?

No, if you use CDN and Kendo UI for jQuery versions released prior to R3 2022 or npm versions released prior to R2 2022, you don’t need to set up the licensing.

Do not include a license file when using Kendo UI versions prior to R3 2022. Including a license file with those versions will cause a KendoLicensing is not defined error.

Can I activate the license using npm if I am working with a Kendo version earlier than 2025.1.211?

No. Projects that use Kendo UI versions released before 2025.1.211 cannot activate the license through npm. For these versions, licensing can only be activated by referencing a JavaScript license key script.

Will the product function without a license file?

Yes, the product will continue to function without a license file. However, a warning message will appear in the browser console if a valid license file is not present. In addition, any pages that contain unlicensed Kendo UI components will receive a banner and select UI components will have a watermark.

Will my license key be exposed in browser developer tools?

Yes, when activating the license by adding a licensing script key to the application, the license key will be visible in the browser developer tools. However, the Script Key is safe to redistribute, it just unlocks the product and is required for the application to run.

I have a `KendoLicensing is not defined` error in the console. What should I do?

If you are using Kendo UI versions after R3 2022 and loading the required scrips asynchronously you need to properly chain the scrips loading order. loadScript is an async method and thus it does not reassure that the kendo.all.min.js is loaded before loading the kendo-ui-license.js.

      Promise.all([
        loadScript(this, ScriptsPath + '/jquery-3.7.0.min.js'),
        loadScript(this, ScriptsPath + '/kendo.all.min.js'),
        loadStyle(this, StylesPath + '/jquery-ui.min.css'),
        loadStyle(this, StylesPath + '/Kendo.css'),
        loadStyle(this, StylesPath + '/kendo.common.min.css'),
      ])
        .then(() => {
        loadScript(this, ScriptsPath + '/kendo-ui-license.js').then(() => {
          console.log('Files loaded');
          this.scriptsLoaded = true; 
        });
      })
        .catch(error => {
        console.error('Error loading KendoUI', error);
      });

When using a custom-built script (custom.min.js) generated through the Download Builder tool, the resulting bundle does not include the licensing code referenced from node_modules. Because of this, license activation through npm is not supported for custom-built bundles.

To resolve the watermark banner, you can choose one of the following approaches:

Option 1: Activate the license using the JavaScript license key. Add the JavaScript license script file to your project to enable license activation for custom bundles.

Option 2: Switch to using ECMAScript (ESM) modules from npm Instead of relying on custom-built bundles, you can transition to the ESM distribution provided via npm. This allows license activation through the @progress/kendo-licensing package.

To use the ESM modules:

1.Install the package:

shell

npm install --save @progress/kendo-ui

Import only the required modules, for example: