IPS Glow vs Backlight Bleed: How to Tell Them Apart and Fix Them

What backlight bleed, IPS glow and clouding look like

All three problems belong to LCD screens, the kind with a backlight behind the picture (IPS, VA and TN monitors, most laptops, LED and QLED TVs). They show on dark content, and they are easiest to see on a black screen in a dark room. OLED screens have no backlight, so they do not bleed, glow or cloud.

Backlight bleed

Light from the backlight escapes around the edges of the panel. You see brighter patches or streaks along an edge or in a corner, often yellowish or bluish. The key sign: the patch stays in the same place and keeps the same shape whether you look from straight on, from the side or from further away. RTINGS separates the two the same way: glow only appears when you view the screen from an angle, bleed does not depend on it. Dell describes leakage as uneven backlight distribution that can be a defect when it significantly affects viewing.

IPS glow

A soft, silvery or slightly colored shine in the corners of an IPS panel. It grows when you look at the screen from an angle and shrinks or moves when you center your eyes. Because you always see the corners of a screen at a slight angle, especially on a big monitor up close, some glow is present on every IPS panel. Dell and RTINGS both call it a characteristic of IPS technology, not a fault.

Clouding

Blotchy lighter areas in the middle of the screen rather than at the edges. RTINGS describes it on TVs as brighter patches caused by the backlight not being spread evenly. Samsung calls the same effect "MURA" and says every TV will have a different level of it.

Flashlighting and blooming

Flashlighting is the TV name for bright beams that look like a flashlight shining in from the corners, a strong form of bleed. Blooming is a halo around bright objects on a dark background on screens with local dimming, because each dimming zone is much bigger than a pixel. Apple explains blooming this way for its mini LED displays. Blooming is a local dimming trait, not bleed.

How to test for backlight bleed and IPS glow

You need a black image that fills the whole screen and a few minutes. Our black screen does exactly that; the screen test adds dark gray, uniformity and near black patterns for a closer look.

1. Warm the screen up. Dell suggests letting a monitor run for about 30 minutes before you judge it.
2. Use normal settings. Set brightness to where you really use it. Dell's guide for telling glow from leakage suggests 30 to 50% brightness. Turn off dynamic contrast and eco modes for the test.
3. Sit where you normally sit. Eyes level with the middle of the screen, about arm's length from a monitor.
4. Open the black screen and go full screen. Press F or click the preview. Make sure the mouse pointer and any overlays are hidden.
5. Look in a dim room first, then with the lights on. Note any bright areas, where they are and their color.
6. Move your head. Lean left and right, stand up, then step back two or three steps. RTINGS suggests tilting the screen or looking from different angles to see whether the corners change.
7. Sort what you saw. Patches that change strongly with your position are IPS glow. Patches that stay put are bleed (at the edges) or clouding (in the middle).
8. Check dark gray too. In the screen test, step to the 10% and 20% gray patterns. Uneven areas there are what you will notice in dark movie scenes and games.

What a browser test cannot do: a web page cannot measure uniformity in numbers. Reviewers such as RTINGS photograph a test pattern with a fixed camera setup and calculate how far the screen is from perfectly even. Our pages give you the pattern; your eyes (and your camera) do the judging.

Backlight bleed vs IPS glow vs clouding: quick comparison

OLED screens do not appear in this table: their pixels make their own light, so RTINGS measures them with essentially perfect black uniformity.

What causes backlight bleed and IPS glow

Why LCDs bleed

An LCD does not make light. A backlight shines through layers of diffusers, a liquid crystal layer and filters, and the liquid crystals block light to make dark areas. They never block all of it, and light that sneaks around the edges or through uneven layers shows up as bleed and clouding. RTINGS names three main causes:

• Backlight design. Edge lit screens have their LEDs only along the edges and tend to have the worst uniformity; full array screens spread LEDs behind the whole panel and tend to do better. Some edge lit models are still very good.
• Uneven pressure from the frame. The panel and diffuser layers are slightly flexible, so small differences in pressure from the frame or internal parts change how light spreads. Shipping damage can do the same.
• Uneven LEDs. One LED can be slightly brighter than its neighbor, and differences can appear over time as parts age.

Because assembly varies, RTINGS stresses that black uniformity differs between individual units of the same model. Two copies of the same monitor can look quite different.

Why IPS panels glow

IPS glow is a viewing angle effect. Light passing through the panel at an angle is not blocked as well as light going straight through, so the parts of the screen you see at an angle look lighter on black. LG's monitor support page says light leakage from a viewing angle of 40 degrees or more from the top, bottom or sides is normal for LCD design. On a large or close monitor, the corners are always at some angle to your eyes, which is why glow sits in the corners.

How to reduce backlight bleed and IPS glow

Fixes that help

• Lower the brightness or backlight setting. Bleed scales with the backlight. Samsung's support pages suggest reducing brightness for clouding, and Dell's checklist starts with seeing whether brightness changes the problem.
• Add some room light. RTINGS points out that using a screen in a brighter room does not change the screen, but it changes what you notice. A lamp behind or beside the screen makes both glow and bleed far less visible.
• Sit centered and a bit further back. For glow this is the main fix. Raise or lower the monitor so your eyes are level with the middle of the screen. Moving back reduces the angle to the corners. LG suggests adjusting height and angle to stay within a good viewing angle.
• Try local dimming, if your screen has it. RTINGS notes that local dimming can improve black uniformity, although on edge lit models it can cause blooming instead. Try each level on a dark movie scene.
• Keep TVs cool. Samsung advises taking a TV out of an enclosed cabinet so it can cool normally when you see uneven backlight.
• Exchange the unit. Because uniformity varies between units, RTINGS suggests trying another copy of the same model before switching models. Within the store's return window this is usually the easiest route.

Fixes that do not help, or are risky

• Software, drivers and pixel fixers. Bleed and glow are light leaking physically. No app, driver or flashing video changes them. A pixel fixer is for stuck pixels only.
• Loosening screws or massaging the panel. RTINGS reports that loosening or tightening frame screws can reduce flashlighting on some TVs and that very gentle rubbing with a soft cloth sometimes helps clouding, but it also warns the screw method can cause more problems than it solves. Pressing on a panel can crack it, and Samsung notes physical damage is not covered by its warranty. Talk to the seller first.
• Taping the edges or bending the frame. Home remedies like these risk damage and usually end any chance of a return.

When backlight bleed counts as a defect

Manufacturers judge light leakage under specific conditions, and those conditions are brighter than a dark room:

• ASUS says to check for leakage with at least 150 lux of ambient light (typical office lighting) and not in a dark room. Leakage that shows only in low light is, in its words, normal.
• Dell says its monitors are inspected at 150 lux, that some leakage on dark backgrounds in dark rooms is within specifications, and that gaming monitors used below about 70 lux may show some leakage.
• LG treats leakage seen from 40 degrees or more off center as normal, and says edges looking darker than the center is also normal because of how the light guide is designed.
• Samsung says clouding is common on LCD TVs and every TV will have a different level of it.

So in practice: bleed you only see in a pitch dark room at full brightness is unlikely to count as a warranty defect. Bleed or clouding that you can see during normal use with the lights on, that is lopsided, or that is clearly worse than another unit of the same model is worth raising. Policies differ by brand and region, so check your model's warranty terms and your retailer's return policy, which is often more flexible in the first days.

What to send with a claim

1. A photo taken in a normally lit room, straight on, with the brightness setting noted.
2. A note of where the bleed is and that it does not change when you move (so it is not IPS glow).
3. If possible, a comparison with an identical model. Dell's own troubleshooting suggests putting the same image on identical monitors to see whether one is clearly worse.

Monitors, laptops, TVs and phones

• Monitors. IPS monitors show glow; VA monitors tend to have better black uniformity overall, according to RTINGS measurements across hundreds of models, though every panel type varies. TN panels show leakage mainly at extreme angles, per Dell.
• Laptops. Many laptop screens are IPS type LCDs, so the same glow and bleed rules apply. Check with the lid at your normal angle.
• TVs. Clouding and flashlighting are the TV names for bleed. Test with near black rather than pure black, because many TVs switch the backlight off on a fully black frame. Local dimming changes the look a lot, so test with your usual picture mode.
• Phones and tablets. Phones with OLED screens cannot bleed. LCD phones and tablets can show slight edge bleed. Mini LED tablets and laptops can show blooming around bright objects instead, which Apple describes as a trade off of local dimming.

How to avoid backlight bleed when you buy a screen

• Want no bleed or glow at all? Choose OLED. The trade off is burn in risk; see image retention vs burn in.
• Watch in the dark a lot? Among LCDs, VA panels and full array local dimming generally give more even blacks than IPS and edge lit designs.
• Read uniformity results, not only specs. Reviews that photograph black uniformity show you the typical result, but remember your unit can differ.
• Test on day one. Run the black screen and the screen test as soon as the screen arrives, together with the dead pixel test, so you are inside the return window if something is wrong. The dead vs stuck pixel guide explains what to do about pixel faults.