notch

A notch is a rectangular or rounded recess cut into the top of a display panel, typically on a mobile phone or tablet, that accommodates the front-facing camera, proximity sensor, ambient light sensor, and microphone while preserving usable screen area below it. The notch represents a compromise between industrial design (thinner bezels, larger screens) and the unavoidable mechanical reality that a camera lens and its sensor require depth and space.

Early smartphone designs housed all front sensors in a thick bezel above the display. As screen-to-body ratios improved, manufacturers faced a choice: accept wider top bezels or cut into the display itself. The notch emerged around 2017 as a way to push sensors and camera into that otherwise wasted corner space. Different implementations vary in width, depth, and shape; some use a teardrop profile (single narrow notch for camera only), while others use a wider rectangular notch (camera plus multiple sensors). The notch width typically ranges from 25mm to 40mm depending on the lens and sensor configuration.

From a display manufacturing standpoint, a notch requires precise masking during the LCD or OLED panel etching process, or in some cases, physical beveling of glass in front of the sensor stack. The glass and polarizer layer must be carefully routed around the camera module to avoid light leaks or sensor flare. Thermal management becomes tighter in the notch area since the camera module generates heat in close proximity to the display substrate.

The notch creates a software challenge: operating systems must define which screen coordinates are usable by applications. Android and iOS both reserve the notch area, treating it as a non-drawable region. Apps that use fullscreen modes must either letterbox content, flow around the notch, or use custom layouts to handle this dead zone. Some devices offer software options to hide the notch effect by blacking out the adjacent screen area, trading display real estate for visual symmetry.

Notch adoption peaked around 2018, 2019, after which alternative solutions gained traction: punch-hole cameras (smaller, circular cutouts), under-display cameras (sensors integrated beneath the screen material), and side-mounted selfie cameras on rotating or pop-up mechanisms. However, the notch remains standard on most mid-range phones and many flagship devices where manufacturing cost and optical quality remain more important than aesthetics.