Voyant provides a hosted version of their tools online which you can access at https://voyant-tools.org. You may wish to install the Voyant server as a stand-alone version on your computer, however, which carries a number of potential benfits, including performance optimization, reliability, security, and privacy. The following section provides instructions on installing a local version of Voyant.
Before downloading the Voyant Server to your computer, make sure that you have Java installed. (Note that the Voyant Server currently requires an older version of Java and may not work on versions newer than 11).
Navigate to the latest release and download the VoyantServer zip file. Unzip the file on your computer (making sure to actually extract the contents into a real directory) and double-click on the VoyantServer.jar file. Mac users may encounter some security precations when opening the file in OS X — Ctrl-click on the VoyantServer.jar, select open and confirm the opening to circumvent this.
Once you open VoyantServer.jar a controller application will appear, which allows you stop stop the server, see error messages, change settings, etc. and a new browser will appear with Voyant Tools. That's it, you're ready to get started!
(These instructions are borrowed from the VoyantServer GitHub repository).