Skip to Content

iPhone Auto-Brightness Not Working (Not or Keeps Dimming)

When in a dimly lit room or in a bright outdoor area, you don’t want to have to constantly adjust the brightness of your iPhone screen manually, which is why Auto-Brightness was created. What can you do if Auto-Brightness on your iPhone suddenly stops working?

If Auto-Brightness on your iPhone is not working or keeps dimming on its own, try turning on the Auto-Brightness feature, turning off the Auto-Brightness feature, reset the Auto-Brightness feature, and be sure that your iPhone is not too hot from either the sun or prolific use.

iPhone on pastel table background

The brightness of your iPhone screen has a major impact on how well you are able to see the content within this device. If your screen is too bright, it may be difficult to decipher characters and letters, causing your eyes to strain or if it is too dim, you may have the same strain, but in an effort to see a very dark picture. Auto-Brightness is a great tool to keep your screen at the perfect brightness level at all times, so what can you do when it stops working?

iPhone Auto-Brightness Not Working

Auto-Brightness is a feature that can be turned on by users to allow their phone to do the screen adjusting for them. This feature picks up on your environment and its light levels, then sets the screen at a brightness level that is most appropriate for the settings. By doing this, iPhone users are able to use their phones with ease no matter where they are, without ever having to adjust the brightness manually.

However, if the Auto-Brightness on your iPhone is not working, you want to first make sure that you have turned the feature on, as this is not always automatically set up. To do this, go to ‘Settings’ > ‘Accessibility’ > ‘Display & Text Size’ > then turn on ‘Auto-Brightness.’

iPhone Keeps Dimming

Drinking morning coffee and using iPhone

If you are in a dark or dimly lit area that is either caused by decreasing natural light or artificial light, your iPhone is going to automatically dim its screen to better suit the user. This is welcomed most of the time, but in those moments when the user wants their phone to stay at a higher brightness level, it can be incredibly frustrating when their iPhone continually dims. If your iPhone keeps dimming, ready below to find out how to stop this event.

If your iPhone keeps dimming, you will need to turn off the ‘Auto-Brightness’ feature within your iPhone. To turn off this feature, go to ‘Settings’ > ‘Accessibility’ > ‘Display & Text Size’ > then turn off the ‘Auto-Brightness’ Feature. This will prevent your screen from dimming automatically.

iPhone Not Dimming

Looking at food pictures on iPhone

On the opposite end of the spectrum, there are times when iPhone users need their screen to dim, but it will not do so. Although this may not seem like too much of a hindrance, this can be incredibly inconvenient when you are in a situation where having a bright screen would be considered interruptive, such as at a movie theatre. If Auto-Brightness is turned on within your iPhone, dimming should happen automatically, but what do you do if it is not?

If your iPhone is not dimming and you have confirmed that Auto-Brightness is turned on (see previous section: ‘iPhone Auto-Brightness Not Working’), reset this feature by turning it off and back on again. Go to ‘Settings’ > ‘Accessibility’ > ‘Display & Text Size’ > then turn the feature off and on.

iPhone Keeps Dimming While Watching Videos

Using iPhone at night out

When you are watching a video, it is likely that you prefer the brightness to be at a relatively high level so that you are not only able to see exactly what is going on within each picture, but you are not straining your eyes to do so. As true as this may be, some iPhone users have expressed complaints of their screen dimming when they are in the middle of watching a video. Why is this happening and what can you do to fix it?

If your iPhone keeps dimming while watching videos, it could be that Auto-Lock is turned on. This feature will automatically dim your screen during long periods of inactivity, which typically happen when watching videos. To turn this off, go to ‘Settings’ > ‘General’ > ‘Auto Lock’ > ‘Never.’

iPhone Keeps Dimming In Sun

Female student using iPhone on campus

It would seem that if your iPhone is in the sun, your screen would need to be even brighter to be seen well in such harsh lighting. Although this may seem logical, some iPhone users have expressed frustration with their iPhone dimming when in the sun. When this happens, they are not able to see their screen, which either causes them to strain, or forces them to increase the brightness of their screen manually.

If your iPhone keeps dimming in the sun, this is due to heat. When an iPhone is exposed to high heat for even a moment, the screen is dimmed to conserve energy. If you would like to keep this from happening, turn off the Auto-Brightness feature that can be found within ‘Settings.’

iPhone Auto-Dim When Hot

Male using iPhone outside cafe

If you are outside on a hot summer day and your phone is exposed to the sun or it is within a pocket that takes on a lot of body heat, you may notice that your screen suddenly dims. This can also happen when you are playing a game, watching a video, or using a power-draining application, which will cause your phone to heat up. When your phone heats up, what is the purpose of the screen dimming?

If your iPhone auto-dims when it’s hot, this is in effort to conserve power. When your phone heats up, a significant amount of power is used, which if gone on for too long, can cause damage to your phone. Therefore, when your phone gets hot, it will dim in order to save power and prevent damage.

iPhone Keeps Dimming Even With Auto-Brightness Off

Female using iPhone while sitting on bed

It has been previously discussed that the surest way to stop your iPhone from dimming on its own is by turning off the Auto-Brightness feature within Settings. However, if you have turned off this feature and are still experiencing problems with your iPhone dimming on its own, what can you do to stop this from occurring? If your iPhone keeps dimming even with Auto-Brightness turned off, take a look below to find the fix.

If your iPhone keeps dimming even when the Auto-Brightness feature has been turned off, it is likely that this is happening when your iPhone is too hot. This is a protective feature that works outside of Auto-Brightness which forces your phone to conserve energy to prevent overheating.

Related Articles

iPhone Won’t End Call

iPhone Won’t Vibrate: Causes and Solutions

iPhone Not Sending/Receiving Text To/From Android

iPhone Keeps Freezing (Restarting and Closing Apps)

ReadyToDIY is the owner of this article. This post was published on June 27, 2021.

iPhone Won’t Reset/Hard Reset/Frozen