Your Windows or macOS scaling/resolution settings are incorrect.
- Confirm Resolution: Right-click desktop > Display Settings (Windows) or System Preferences > Displays (macOS). Set the resolution to 3840 x 2160.
- Check Scaling: At 4K on a 27" screen, scaling (e.g., 150% on Windows) is normal for readable text. Don't confuse scaling-induced UI size changes with blurriness.
- Signal Source: Ensure you're using a high-speed HDMI or DisplayPort 1.4 cable capable of 4K@60Hz. A poor cable can cause signal degradation.
- Monitor Setting: Open the On-Screen Menu. Go to Picture > Super Resolution+. Turn this off. This is an upscaling feature for lower-res content and can make native 4K text look processed and fuzzy.
IF THAT DIDN'T WORK: In the Picture menu, reset Sharpness to 50 (default). Excess sharpness can create halos and make text look harsh.