In this guide, I’ll show you how to assign specific applications to dedicated workspaces in i3wm, a tiling window manager for Linux. By doing this, you can streamline your workflow by ensuring that certain applications always open in their designated workspace, making your setup more organized and efficient.

✅ Step 1: Identify the Application Class Name

To assign an application to a specific workspace, you need to first identify its class name. This is essential because i3wm uses the window class name to match the application.

1.1. Launch the Application

Open the application you want to assign to a dedicated workspace. For example, if you want to assign Firefox, launch it by running:

firefox &

1.2. Use xprop to Find the Class Name

xprop is a tool used to retrieve window properties. Run the following command and then click on the window of the application you want to assign:

xprop | grep WM_CLASS

  • Explanation:

    • xprop: Launches the window property inspector.
    • | grep WM_CLASS: Filters the output to show only the class information.

1.3. Interpret the Output

You will see an output similar to this:

WM_CLASS(STRING) = "Navigator", "firefox"

  • The output consists of two parts:

    • The first value (Navigator) is the instance name.
    • The second value (firefox) is the class name.

  • For workspace assignment, you’ll need the second value (firefox in this case).

🔧 Step 2: Modify the i3wm Configuration File

Once you have the class name, you can assign it to a specific workspace by editing your i3wm configuration file.

2.1. Open the Configuration File

Use a text editor to open the i3 configuration file:

nano ~/.config/i3/config

2.2. Add the Workspace Assignment

Add the following line at the end of the configuration file:

assign [class="<application_class>"] <workspace_number>
  • Replace <application_class> with the class name you got from xprop.
  • Replace <workspace_number> with the workspace number where you want the application to open.

Example

If you want Firefox to always open in workspace 2 and Terminal (Alacritty) in workspace 1, add:

assign [class="firefox"] 2
assign [class="Alacritty"] 1
  • This ensures Firefox always opens on workspace 2, and Alacritty on workspace 1.

🔄 Step 3: Reload i3wm Configuration

After making the changes, reload the i3wm configuration to apply the new workspace rules:

i3-msg reload

or

Mod+Shift+R
  • Mod is usually mapped to the Super (Windows) key.

🚀 Step 4: Verify the Workspace Assignment

To verify, close the applications and reopen them. They should automatically launch in their assigned workspaces.

🛠️ Tips and Tricks

  1. Assign Multiple Applications to the Same Workspace: You can assign multiple applications to the same workspace by separating them with a comma:

    assign [class="firefox"], [class="Chromium"] 2

  2. Use Floating Windows: If you want specific applications to open in floating mode, you can add:

    for_window [class="pavucontrol"] floating enable

  3. Check Config Syntax: After editing, ensure there are no syntax errors by running:

    i3-msg reload

🎯 Conclusion

By assigning dedicated workspaces for specific applications in i3wm, you can enhance your productivity and keep your desktop environment organized. This setup ensures that your frequently used applications always open where you expect them, streamlining your workflow.

✅ Tip: If you want to explore more i3wm customization options, check out the official i3wm documentation.

📌 Tags: i3wm, Linux, window manager, tiling, workspace management