If you are using the commercial distribution (often installed via npm under the @ckeditor/ckeditor5-* packages) but you have not configured a license key, you will see a warning banner in the editor stating "This is a trial version" or "Unlicensed usage."
<script> window.CKEDITOR_LICENSE_KEY = 'Your-License-Key-Here'; </script> <script src="https://cdn.ckeditor.com/ckeditor5/40.0.0/classic/ckeditor.js"></script> ckeditor 5 license key
| Feature | Details | |---------|---------| | | Opt-in; production keys have no restrictions by default | | Maximum entries | Up to 5 domains or IP addresses | | Wildcard support | *.example.com (subdomains) or 192.168.*.* (IP ranges) | | Key recreation | A new key is automatically created when you update the whitelist | If you are using the commercial distribution (often
Understanding CKEditor 5 License Keys: Commercial vs. Open Source However, if your license is for a Node
If your editor runs entirely in the browser, the license key will be visible in the network tab or source code. That’s expected—license keys are not secrets for frontend-only implementations (they are domain-locked). However, if your license is for a Node.js backend (e.g., PDF export server), treat it like a secret.
The short answer is , but the type of key you need—and whether it costs money—depends entirely on your project's legal licensing. CKEditor 5 is distributed under a dual-licensing model:
Full legal rights to use the editor inside proprietary, revenue-generating software.