Simulate HiDPI ("Retina") scaling on external displays that don't natively report a HiDPI mode to macOS — with a "Looks like" resolution picker in System Settings ▸ Displays, just like a real Retina panel.
Requires macOS 26 (Tahoe) or later. Older releases are not supported.
Local — clone the repo and double-click retinafy.command, or run it
from a terminal:
git clone https://github.com/itsdezen/retinafy.git
cd retinafy
./retinafy.shRemote — run directly without cloning:
bash -c "$(curl -fsSL https://raw.githubusercontent.com/itsdezen/retinafy/main/retinafy.sh)"(Icon customization needs the icons/ folder next to the script, so the
local clone is the more complete option; the remote one-liner still works
for the core HiDPI injection.)
Run the script and follow the prompts:
- Enable HiDPI — pick the external display, then choose how to derive
the "Looks like" resolutions:
- Auto — retinafy reads the display's current (native) resolution and generates the same spread of scale steps macOS computes for a real Retina display ("Larger Text" down to "More Space"), all locked to the display's real aspect ratio.
- Manual — type your own list of resolutions if you want full control.
- Disable HiDPI — remove one installed override, or reset everything back to the macOS default.
Reboot after enabling or disabling for the change to take effect. The boot logo may look oversized on the very first reboot only.
- Only writes under
/Library/Displays/Contents/Resources/Overrides— never touches/System, never requires disabling SIP, never installs a kernel extension. - The built-in display is detected and excluded before any display list is ever shown — it cannot be selected, and nothing in this tool can write to its profile. Always double-check the display name printed before confirming, especially on unfamiliar hardware.
- Everything is reversible: use the in-app "Disable HiDPI" option, or delete
/Library/Displays/Contents/Resources/Overridesentirely. - If a change ever leaves a display unusable, boot into macOS Recovery,
open Terminal, and run the helper script generated at
~/.retinafy-disable(or manually delete the folder above from the mounted system volume).
Some monitors drop to a lower resolution after sleep/wake when using a plain override. retinafy can optionally patch a couple of feature-flag bytes in the display's own EDID (embedded only in its override file — your monitor's actual firmware is never touched) to work around this. It's only offered on Intel Macs, since Apple Silicon has no real EDID to read in the first place.
MIT — see LICENSE.