A Mac taskbar for multiple monitors: windows and Spaces

A second monitor gives your work more room, but it can also make a window harder to find. A useful Mac taskbar setup starts with a choice: should each screen list its own windows, or should both screens give you access to the whole workspace?

This guide uses a simple example: a draft on your Mac’s screen, a reference on an external monitor, and another document on a second desktop. Set up the displays in macOS first, then choose which of those windows Dockline should list.

Start with the macOS display setup

For different work on each screen, use an extended desktop. Mirroring repeats the desktop instead. In System Settings → Displays, select the external display and choose its role in Use as. Apple explains the options in Extend or mirror your Mac desktop.

A display is a physical screen; a Space is a virtual workspace. You can create another desktop in Mission Control and keep a document there without adding another monitor. Apple’s Spaces guide shows how to add desktops and move a window between them.

For a separate set of Spaces on each screen, check Displays have separate Spaces in System Settings → Desktop & Dock → Mission Control. Apple also requires this option for Split View on other displays and for Stage Manager. See Desktop & Dock settings. Keep your preferred system setup in mind when comparing the taskbar’s filters below.

Choose what each Dockline panel lists

Open Dockline’s Displays and desktops settings. Two controls work together:

Show windows from displays: choose Current display for windows on the screen containing that panel, or All displays to include windows from the other screens too.
Show windows from desktops: choose Current desktop to narrow the list to the current desktop, or All desktops to include windows on other desktops.

Both filters apply. Choosing All displays does not cancel a Current desktop filter. Choosing All desktops does not cancel a Current display filter. Changing these controls changes the list of windows; it does not move your documents.

Start with Current display + All desktops if each screen has a clear role: writing on one, reference material on the other. Try All displays + All desktops if you prefer a broader list regardless of where a window is placed. The useful choice is the one that makes your next window easy to identify.

Try three windows across two screens

Prepare a small workspace. Open three separate document windows with distinct titles. Put the draft on the Mac’s screen and the reference on the external display. Use Mission Control to put the third window on another ordinary desktop on the Mac’s screen. These are window examples, not browser tabs.
Begin with Current display + All desktops. On the Mac’s panel, look for the draft and the third document. On the external display’s panel, look for the reference. Click a named button and check that it brings you to the intended window.
Change only the display filter to All displays. Check whether the reference now joins the other windows on the Mac’s panel. Decide whether that wider list saves you effort or adds clutter.
Try Current desktop. Switch desktops and watch which buttons remain. If the third document drops out of the list, return to All desktops before treating it as a missing window.
Repeat with the apps you use. Include minimized or full-screen windows only if they are part of your routine. Check focus, titles and the destination desktop on your own setup; app compatibility and window accessibility can vary.

If an ordinary window is absent even with both filters set to All, check Accessibility permission and the app’s window behavior. Optional thumbnails additionally need Screen Recording permission. A missing thumbnail and a missing window button are different symptoms.

Make desktop sections easier to read

With All desktops and Current display selected, Separate windows by desktop is available. It divides the list into desktop sections. Show desktop labels helps identify them; Show desktop buttons adds controls for switching desktops.

Use these controls when the desktop a window belongs to helps you recognize it. If you mainly recognize document titles, start with the window list and add desktop controls when needed. The Windows-style taskbar guide explains how individual buttons and collapsed app groups differ.

Treat window transfers as a separate beta

Finding a window and moving it are separate actions. Dockline has two optional experimental controls: Drag windows between displays and Drag windows between desktops. Both are marked Beta and start off. A transfer that crosses both a display and a desktop needs both switches enabled.

The comparison above does not require either beta. Arrange the sample windows using macOS first. If you later try taskbar transfers, use a saved document and check the destination with your own apps. Compatibility is still being tested; do not assume a result with one window covers full-screen apps, Split View or every display arrangement.

Check the published version

The public installer is Dockline 1.269 for Apple silicon and Intel Macs running macOS 26.5 or later. Review the settings guide and current Trial and purchase options before choosing it for your workflow.