Clouding Test
The Clouding Test shows a dark gray field — set just above pure black, where uneven backlight clouding shows up best — so you can spot cloudy or patchy blotches caused by uneven panel pressure or diffuser irregularities. Click Start Clouding Test in a dim room, step between the two dark shades, and note roughly where on the screen any patches appear, since clouding is distinct from both backlight bleed at the edges and IPS glow at the corners. Run the free ips glow test to check your display for this issue directly in your browser — no download required.
Click Start Clouding Test to fill your screen with a dark gray field in a dim room — set just above pure black, where clouding shows up best. Use the on-screen controls or arrow keys to step between the two dark shades and note roughly where any cloudy or patchy areas appear.
What Causes Monitor Clouding
Clouding is uneven, patchy brightness across an LCD panel's backlight — soft, irregular gray or whitish blotches that become visible against a dark background. It's caused by inconsistent pressure or contact between the LCD panel layers and the backlight/diffuser behind them, often from manufacturing tolerances, a panel that's been under mechanical stress (including tight VESA-mount screws), or normal material expansion as the panel warms up during use. Use the run an input lag test to confirm whether your monitor shows this issue before you adjust settings or return it.
Clouding is most visible on edge-lit LCD panels, where LEDs positioned along the display's edges shine through a light guide plate to spread illumination across the whole screen — any unevenness in that light guide shows up as patchy brightness. Full-array backlit panels, which place LEDs directly behind the whole panel rather than just at the edges, are generally less prone to clouding because the light source is already distributed.
Telling Clouding Apart from Backlight Bleed and IPS Glow
These three display artifacts get confused constantly because they all show up as unwanted light on a dark screen, but they have different causes and different shapes: The run a geometry test works on any screen — laptop, external monitor, or TV — with nothing to install.
| Artifact | Shape | Cause |
|---|---|---|
| Clouding | Soft, irregular patches anywhere on the panel | Uneven backlight/diffuser pressure |
| Backlight Bleed | Bright streaks or blotches specifically at panel edges/corners | Light escaping around the bezel where the backlight meets the frame |
| IPS Glow | A soft glow in corners that shifts position as your viewing angle changes | Inherent to IPS panel technology's light polarization at off-angle viewing |
The key distinguishing test: IPS glow moves or fades as you change your viewing angle or the room lighting, while clouding and backlight bleed stay fixed in place regardless of where you're sitting. Bleed is also almost always confined to the very edges of the panel, while clouding can appear anywhere, including the center.
Which Panel Types Are Most Prone to Clouding
Edge-lit VA and IPS panels see clouding most often, since VA panels in particular already have higher inherent contrast and darker native blacks, which makes any uneven backlight far more visible. Larger panels are also more susceptible simply because there's more surface area for backlight distribution to go uneven across. OLED and Mini-LED displays are essentially immune to clouding in the traditional sense, since OLED pixels emit their own light with no separate backlight layer, and Mini-LED's much higher density of local dimming zones makes uneven illumination far less noticeable even when it exists.
When Clouding Is a Warranty Issue
Mild clouding that's only visible on a near-black screen in a dark room, and invisible during normal use, is common enough on LCD panels that most manufacturers don't consider it a defect. Clouding that's clearly visible during normal SDR content, especially in bright scenes, or that's gotten noticeably worse over time, is a stronger case for a warranty claim or return within the manufacturer's return window. Photograph the issue against a dark gray field (not pure black, which can hide detail) in a dim room, since that's the standard way manufacturers ask customers to document the problem.
Frequently Asked Questions
- Can monitor clouding be fixed once it appears?
- Not reliably at home — clouding is a physical panel/backlight issue, not a software setting. Loosening VESA mount screws slightly can sometimes help if the clouding appeared after mounting, but persistent clouding usually requires a panel replacement or warranty exchange.
- Is clouding the same as a dead backlight zone?
- No. A dead zone is a hard-edged area with no backlight at all (appears as a dark rectangle or band). Clouding is soft, irregular, and represents uneven brightness rather than a complete absence of it.
- Does clouding get worse over time?
- It can, especially if caused by mechanical stress from mounting or shipping — the panel layers can shift further apart over months of use. Clouding that's stable and mild usually stays that way, but any clouding that's visibly progressing is worth documenting for warranty purposes.
- Why do I only see clouding when watching dark movies?
- Clouding is only visible against dark backgrounds because that's the only condition where the uneven backlight has enough contrast against the intended black to become noticeable — under normal bright content, the unevenness is masked by the image itself.
- Do OLED monitors get clouding?
- No — clouding is specifically a backlight/diffuser issue, and OLED panels have no separate backlight (each pixel emits its own light). OLED can suffer from other issues like burn-in, but not clouding in the LCD sense.