Why Is My iPhone No Longer Adjusting Brightness Automatically?

You know the feeling: the sun is blazing, you’re outside with your iPhone in hand – and you can barely make out a single thing on the screen. Or the opposite scenario: you half-asleep reach for your phone just to check the time, tap the screen, and get blinded by a searingly bright display, like someone shining a flashlight straight into your face. Both situations are incredibly annoying – and both point to the same culprit: your iPhone’s automatic brightness adjustment has stopped working.

Before you frantically book an appointment at the Apple Store and brace yourself for a hefty repair bill to replace a supposedly broken ambient light sensor: take a breath. There’s a well-hidden setting you should check first. In my case, after a battery replacement – for reasons I still can’t explain – it had simply been switched off. And that one little toggle was behind all these frustrating symptoms.

The catch? The setting is not where you’d intuitively look for it. If you head to Settings → Display & Brightness and look around the True Tone option, you’re in the right neighbourhood – but still in the wrong place. Sure, it would make sense for it to live right next to the brightness slider, but that would be too easy. Instead, you’ll find it here:

Settings → Accessibility → Display & Text Size → Auto-Brightness (all the way at the bottom)

Once that switch is turned on, your display will automatically adapt to the ambient light around you – bright in sunlight, comfortably dimmed in the dark.

And this isn’t the first time I’ve stumbled across something useful buried in Accessibility settings. It feels like Apple has been quietly relocating features there whenever they’re not used frequently enough to justify a spot in the main menus. Another hidden gem worth knowing about: under Accessibility → Touch → Prefer Cross-Fade Transitions — wait, wrong one. The one you want is Accessibility → Touch → Tap to Snooze / Single Tap to Dismiss – which lets you dismiss your alarm with a simple button press instead of swiping across the screen, just like the good old days.

So next time you’re hunting for a missing feature, it’s worth taking a detour through Accessibility. You might be surprised what’s hiding in there.