Hi James thanks for posting in the Lucid community! Yes you can use the Apple Pencil with the web browser version of Lucidchart and it should largely be functional. Please note however that our dedicated support for Apple Pencil lies with our Lucidchart and Lucidspark mobile apps which will provide you with a better experience. For example the mobile app supports double tapping to convert from Pen to Eraser but the browser does not. I hope this helps! Please let me know if you have any additional questions.