There isn't a traditional "license key" for CKEditor 5 when used under the GPLv2 license. This means you don't need to purchase or activate CKEditor 5 with a license key for most use cases. However, there are scenarios where developers or companies might seek alternative licensing terms:

Have questions about your specific implementation or licensing scenario? Consult the official CKEditor 5 Licensing FAQ or contact CKSource sales directly.

One of the biggest changes in recent versions of CKEditor 5 is the introduction of the "unlicensed usage" notification.

: The Long Term Support edition is available only under commercial terms and provides up to three years of security updates. Open Source : If your project is GPL-compatible, you can use CKEditor 5 for free, but you must still set the licenseKey in newer versions (v44.0.0+) to avoid warnings. Are you setting this up for a personal open-source project company's production environment CKEditor Licensing