I discovered how Apple secretly protects your OLED iPhone or iPad against burn-in ‣ Diverse Daily

Anyone who’s ever considered an OLED TV is familiar with the concept of burn-in. Essentially, the “O” in OLED — its organic electroluminescent layer — is more prone to degradation under heat than synthetic material. When static objects stay onscreen for hours at a time, this can produce image retention, a.k.a. “ghost” patterns. In the long run, color tint and diminished brightness are unavoidable.

Here’s the thing: TV makers are generally upfront about how they try to prevent burn-in. There are often conspicuous settings options devoted to it. Apple is relatively cagey, though, and doesn’t put explicit features on your iPhone or iPad. I decided to do a little research, and as it turns out, it’s relying on both stealth tactics and UI settings to keep your screen attractive as long as possible.

How Apple fights burn-in on OLED iPhones and iPads

A two-front strategy

Putting aside the Apple Watch, the first Apple device with OLED was the iPhone X, and that gives us our starting point. In discussing the Super Retina screens on the X series, the company explains that it uses “special algorithms that monitor the usage of individual [OLED] pixels to produce display calibration data.” This is used to adjust the brightness of pixels on the fly, helping to “reduce visual effects from burn-in and to maintain a consistent viewing experience.”

That’s still a little vague, but other, unofficial sources suggest that Apple is exploiting two well-known techniques: pixel shifting and dithering. Pixel shifting involves slight, unnoticeable shifts in pixel positioning, ensuring that static graphics are never actually in the same place for that long. I don’t really question this one — it’s universal on OLED TVs, and without it, your iPhone or iPad’s status bar would probably haunt every app. Models with always-on (AOD) technology might see their lockscreens burned in as well.

As for dithering, that spreads illumination duties across multiple subpixels, continuously varying their voltage instead of foisting everything on just one pixel. It’s hard to say for sure whether Apple is relying on this, but it’s also hard to imagine that Apple would ignore a tried-and-tested method with no serious downside.

Apple’s other weapons involve iOS and iPadOS features that nominally have other uses. Auto-brightness, for example, isn’t just about protecting your eyes or adjusting to sunlight. It extends battery life, and most importantly for OLED screens, it keeps pixels from getting any hotter than they need to. High heat accelerates degradation, so it’s best to keep your screen just bright enough to be legible at a glance. Apple acknowledges these things in that Super Retina guide I mentioned earlier.

Similar thinking is going on with lockscreens. Auto-lock either turns your screen off completely or switches it into AOD mode. When your AOD lockscreen is active, brightness is sharply reduced, and refresh rate is lowered to just 1Hz, i.e. one update per second. In fact, AOD would be completely impractical otherwise, simultaneously reducing OLED lifespans while preventing you from making it a full day (or likely half a day) on a single charge.

Next up is Dark Mode. A lot of people enable it for aesthetic reasons, or else keeping their eyes from bursting into flames at night. Dark pixels are inherently less power-hungry, though, particularly in the case of OLED. Unlike LCDs, OLED displays can completely shut off individual pixels, meaning the more black you have onscreen, the better. Tech-savvy device owners will often use minimalist wallpapers to push longevity as far as it can possibly go.

One major difference versus TVs is that Apple doesn’t seem to use automated pixel refresh cycles. Those are meant to even out pixel wear, making burn-in unnoticeable. Presumably Apple is avoiding this because of the wait times involved. Long TV refreshes can take up to an hour, and a “short” cycle can still last 5 to 10 minutes. During both, your TV is inaccessible. iPhones and iPads do have smaller screens to manage, but they also have less predictable usage patterns, and can frequently be mission-critical. You’d be rightfully angry if you went to call an ambulance at 3AM, only to discover your iPhone was too busy looking pretty. Apple doesn’t want that kind of backlash.