The Webview is a specialized Tool for previewing and debugging your web application.
By default, when your Repl exposes an HTTP server, the Webview will automatically open. If you don't want this intrusive behavior, there is a setting to turn it off.
Click on the Pencil icon on the right side of the URL bar to add a custom domain to your Repl. For instructions on how to do this, see Connecting your domain to your Repl.
Click on the Wrench icon to open the developer tools in the Webview. The Developer tools will allow you to see console logs, inspect elements, view network requests, and more.
For more information on how to use the Developer Tools, check out the Eruda Demo and Documentation
Why can't I edit the URL in the webview?
The URL shown in the webview is read-only and points to the root route of your Repl's web output through the
<iframe> HTML element. To test a different route, click the button on the far right to open your project's web output in a new browser tab.
What's the difference between the Webview and an Extension?
The Webview is a normal iframe and an Extension establishes a special handshake with the Replit workspace. Read more here.