To set up LWC Local Development, install the server, enable and authorize a Dev Hub org, and create a scratch org. To use the LWC Local Development, you must develop Lightning web components in a Salesforce DX project.
Install the LWC Local Development Server
Run this command from a command-line interface.
sfdx plugins:install @salesforce/lwc-dev-server
Troubleshooting Tip: Due to a known issue, it’s likely you’ll see several errors when you install the plug-in. Run
sfdx plugins --coreto see if the plug-in is installed. If yes, try to start the Local Development server. If successful, you’re good to proceed.
After you select SFDX: Preview Component Locally, the Command Palette displays a list of preview options. You can choose to preview your component in the desktop browser or in a virtual mobile device (iOS or Android). Mobile previews require additional setup. See Preview Lightning Web Components on Mobile in the Lightning Web Components Dev Guide.