Not sure where to start? Use the manual brightness helper.

SDR white is not the panel’s absolute maximum

On an XDR or EDR-capable display, macOS can reserve brighter output for highlights in extended-range content. That extra capacity is called headroom. The amount is dynamic: it depends on the display, active mode, system conditions, and what macOS reports at that moment.

A conventional brightness slider changes the display’s overall setting. Luxa instead renders an enhanced copy of the visible desktop into a floating extended-range Metal surface, allowing ordinary whites and highlights to use some of the reported headroom.

How Luxa stays honest about the number

Luxa reads the display’s current and potential extended dynamic range component values, clamps them to its 200% product ceiling, and applies any smaller user, battery, or thermal cap. Standard displays are handled separately with a much smaller adjustment.

The percentage is a control multiplier for Luxa’s enhancement—not a calibrated claim that panel luminance doubles. Content, local dimming, ambient light, and macOS display management all affect the visible result.

Reference modes and HDR settings matter

Some Apple displays offer reference modes tuned for different workflows. A photography, video, or custom reference mode can intentionally constrain luminance. Check Display settings if the available Luxa range is lower than expected, and do not override a calibrated workflow merely to make the interface brighter.

Luxa is a readability utility, not a color-grading control. Reset to 100% or quit Luxa before making color-critical judgements.

Further reading from primary sources

Apple: play HDR video on Mac Apple: use reference modes
Straight answers

Frequently asked questions

Is XDR the same as HDR?

They are related, but XDR is Apple’s term for displays and workflows with extended dynamic range performance. Luxa relies on the EDR values macOS exposes to apps.

Will Luxa alter screenshots or saved files?

No. Luxa changes the on-screen presentation. It does not modify your documents, images, or exported files.