Debug JavaScript in Chrome

Make sure the JavaScript and TypeScript bundled plugin is enabled in the settings. Press CtrlAlt0S to open the IDE settings and then select Plugins. Click the Installed tab. In the search field, type JavaScript and TypeScript. For more information about plugins, refer to Managing plugins.

Make sure the JavaScript Debugger bundled plugin is enabled in the settings. Press CtrlAlt0S to open the IDE settings and then select Plugins. Click the Installed tab. In the search field, type JavaScript Debugger. For more information about plugins, refer to Managing plugins.

Configure the built-in debugger as described in Configuring JavaScript debugger.

To have the changes you make to your HTML, CSS, or JavaScript code immediately shown in the browser without reloading the page, activate the Live Edit functionality. For more information about the live editing functionality, refer to Live Edit in HTML, CSS, and JavaScript.

Set the breakpoints in your code.

Start the application in the development mode, for example, using an npm script.

The Run tool window or the Terminal shows the URL at which your application is running. Hold CtrlShift and click this URL link. CLion starts a debugging session with an automatically generated configuration of the type JavaScript Debug.

Set the breakpoints in the JavaScript code, as required.

Run the application in the development mode. Often you need to run npm start for that.

When the development server is ready, copy the URL address at which the application is running in the browser - you will need to specify this URL address in the run/debug configuration.

Create a debug configuration of the type JavaScript Debug: go to Run | Edit Configurations, in the Edit Configurations dialog that opens, click the Add button () on the toolbar and select JavaScript Debug from the list. In the Run/Debug Configuration: JavaScript Debug dialog that opens, specify the URL address at which the application is running. This URL can be copied from the address bar of your browser as described in Step 2 above. Click OK to save the configuration settings.

Select the newly created configuration from the Select run/debug configuration list on the toolbar and click the Run button () next to the list. The URL address specified in the run configuration opens in the browser and the Debug tool window appears.

In the Debug tool window, proceed as usual: step through the program, stop and resume the program execution, examine it when suspended, view actual HTML DOM, run JavaScript code snippets in the Console, and so on.

Set the breakpoints in the Workers to debug.

If you are using Service Workers, make sure the Allow unsigned requests checkbox is selected on the Debugger page (Settings| Build, Execution, Deployment | Debugger). Otherwise your service workers may be unavailable during a debug session.

Create a debug configuration of the type JavaScript Debug as described above in Debugging client-side JavaScript running on an external web server.

Select the newly created configuration from the Select run/debug configuration list on the toolbar and click the Debug button () next to the list.

The HTML file specified in the run configuration opens in the browser and the Debug tool window opens with the Frames list showing all the Workers:

To examine the data (variables, watches, and so on) for a Worker, select its thread in the list and view its data in the Variables and Watches panes. When you select another Worker, the contents of the panes are updated accordingly.