Can I fit a larger desktop onto a lower-resolution monitor?

Yes. Create a virtual screen with a larger desktop size and mirror it to the physical monitor. The monitor shows a reduced image of that desktop, so windows and text become smaller. Its physical pixel count stays the same, and fine detail can become harder to read.

For example, a 2560 × 1440 virtual desktop mirrored to a 1920 × 1080 monitor fits more content than that monitor's native-sized desktop. This is different from choosing 1920 × 1080 HiDPI: HiDPI adds rendering detail at the same logical desktop size. It does not by itself add workspace.

The macOS scaling explanation distinguishes desktop size, rendering pixels and physical output.

  1. Open Settings > Displays > Overview > Create New Virtual Screen… and choose a preset matching the monitor's aspect ratio, such as 16:9 - HD/4K/5K/6K.
  2. Create and connect the virtual screen. In its Display Mode menu, choose an available desktop size larger than the physical monitor's native size.
  3. Configure mirroring so the physical monitor shows the virtual screen's desktop. Check the direction: the virtual screen supplies the image.
  4. Adjust the virtual screen's desktop size until text and windows are comfortable. When matching another monitor, compare the same window on both. Matching resolution percentages alone does not account for different physical screen sizes.

Basic preset virtual-screen creation and connection do not require Pro. Configuring mirroring in BetterDisplay requires Pro. You can also set up ordinary mirroring in macOS Displays settings.

Streaming is an alternative when you need its presentation features. It requires Pro and Screen Recording permission. With streaming, both desktops remain in the arrangement: place the virtual source where you want to work and the physical target where the pointer will not easily wander onto it. See stream pointer routing.

This gives you more workspace, not the sharpness of a physically higher-resolution panel. See text clarity and pixel mapping and virtual-screen resolution choices.