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Hardware

What is nits?

Nits measure display brightness (luminance): 1 nit equals 1 candela per square meter. More nits mean a brighter screen, useful in bright rooms and for HDR.

What are nits?

A nit is the unit used to rate how bright a display is. Technically it measures luminance, and 1 nit equals 1 candela per square meter (cd/m²). Monitor, laptop, phone and TV spec sheets list brightness in nits, and a higher number means the screen can put out more light.

Why brightness matters

  • Bright rooms and outdoors: sunlight and nearby windows wash out a dim screen. Laptops, tablets and phones used outdoors need more nits to stay readable.
  • HDR: high dynamic range content needs bright highlights next to dark areas. A display that can't get bright enough shows HDR content flat or dim.
  • User complaints: "the screen looks dim even at 100%" can mean a low-brightness panel for the environment, or a failing backlight.

Reading a brightness spec

Spec sheets may show two numbers. Typical or full-screen brightness is what the display can sustain across the whole screen. Peak brightness is reached only on a small area, such as a highlight in an HDR scene, and often only briefly. Compare like with like.

VESA's DisplayHDR certification tiers are named for their minimum peak brightness: DisplayHDR 400 requires at least 400 nits, DisplayHDR 600 at least 600 and DisplayHDR 1000 at least 1,000. Higher tiers also set stricter requirements for black level and local dimming.

Nits vs. lumens

Projectors are rated in lumens (usually ANSI lumens), which measure the total light the projector puts out, not the brightness of a screen surface. A bigger image or a brighter room needs more lumens. Don't compare a monitor's nits with a projector's lumens; they measure different things.

Troubleshooting a dim screen

  1. Check the brightness setting (in Windows, Settings, System, Display). Turn off adaptive brightness and battery saver dimming while you test.
  2. Check the power plan and the monitor's own menu for eco or power-saving modes.
  3. Shine a flashlight at the screen. If you can faintly see the image, the LCD is working but the backlight (or, on older CCFL panels, the inverter) has failed.
  4. Keep age in mind: backlights and especially OLED panels lose brightness over years of use.

For the CompTIA A+ exam

Nits aren't named in Core 1 (220-1201), but brightness ties into two objectives. Objective 3.1 covers display types such as LCD, OLED and Mini-LED, plus the inverter, and objective 5.3 lists a dim image among display symptoms. A screen that's dim at full brightness, with the image faintly visible under a flashlight, points to a backlight or inverter failure.

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Related terms

backlight

The backlight is a lighting system that illuminates the display of electronic devices, such as LCD (Liquid Crystal Display) screens, to make the content visible in low-light or dark environments.

full-array

Full-array is an LCD backlight with LEDs behind the whole panel, often split into local dimming zones (FALD) for deeper blacks than edge-lit screens.

HDR

High Dynamic Range (HDR) is a imaging and display technology that captures, stores, and displays a greater range of luminosity levels and color information than standard dynamic range, enabling more realistic and visually vibrant content with enhanced contrast and detail in both bright and dark areas.

inverter

An inverter is an electronic device that converts direct current (DC) electricity into alternating current (AC) electricity, enabling the use of AC-powered devices and appliances.

LCD

A liquid crystal display (LCD) is a type of flat-panel display that uses the light-modulating properties of liquid crystals to produce images on a screen.

LED backlight

An LED backlight is a type of display technology that uses light-emitting diodes (LEDs) to illuminate the pixels of a liquid crystal display (LCD) panel, providing illumination and improving image quality.

Mini-LED

Mini-LED is a display backlight technology that uses an array of smaller, high-density LED lights to provide enhanced contrast, brightness, and local dimming capabilities compared to traditional LCD displays.

OLED

OLED (Organic Light-Emitting Diode) is a display technology that uses organic compounds to emit light when an electric current is applied, enabling the creation of thin, energy-efficient, and high-contrast displays.

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