How can I send a lower-resolution signal instead of a scaled desktop?

Select a display mode that changes the actual output timing, then verify the incoming resolution in the monitor’s own information menu. Selecting a smaller desktop size alone can leave the video signal at the panel’s native resolution: macOS scales the desktop before sending it.

For example, a 1920 × 1080 desktop on a 2560 × 1440 monitor can still arrive as a 2560 × 1440 signal. A monitor’s Pixel-for-Pixel or similar option acts on that incoming signal, so it cannot recover a smaller unscaled desktop from a signal that the Mac has already enlarged. The name and availability of this monitor option depend on the model.

Open BetterDisplay’s Display Mode menu and inspect the available modes at the desired size, including different refresh-rate variants. Use Filter… > Show All if necessary. Rows with the same desktop dimensions can represent different modes. Verify what the monitor actually receives after selecting one. A working lower-resolution timing may appear as an ordinary or variable-refresh-rate entry.

Do not treat the Unsafe marker as an “unscaled output” label. It reflects the mode’s reported safety flag. An unsafe entry can fail to switch, and the working physical timing may be an unmarked entry. A mode’s presence in the list does not guarantee that macOS will apply it.

If none of the available modes changes the signal as required, a carefully prepared custom EDID advertising the desired supported timing is an advanced possibility on compatible Apple-silicon connections. Applying it requires Pro and can interrupt the picture. Follow the EDID reference’s backup and recovery guidance. It is not a guarantee that every Mac and monitor will accept a particular timing. Editing native panel pixel resolution merely to rename the panel is not a dependable substitute. See native dimensions and scaling.

For an alternative that only needs a smaller visible play area, a virtual desktop streamed with 1:1 Pixel Mapping can place a smaller image within the physical output. That leaves the connection timing unchanged and can add latency. See stream size and alignment before choosing that approach for games.