The iPhone's home button is responsible for at least six different default functions—waking the lock screen, opening the multitasking interface, scanning Touch ID, summoning Siri, triggering Reachability, and going to the home screen. Objectively, that's a lot to ask of one single button.
With all of this stuff going on, you'll sometimes encounter situations where you didn't mean to trigger a certain function. Other times, you'll double-click or triple-click, but the action you were trying to perform isn't registered. To help get things under control once and for all, or to get even more functionality out of your home button, check out the tips below.
This guide assumes you're running the most up-to-date software, iOS 9, on your iPhone. These tips will also work the same in the new iOS 10, and some may work on older iOS versions, too.
Reachability was first introduced on the iPhone 6 variants to make the larger screens easier to use with only one hand, so if you don't have an iPhone 6 or 6s variant, you won't see Reachability anywhere. It's one of my favorite iOS features on my iPhone 6, but it's frustratingly easy to trigger by accident, because all it takes is two inadvertent touches.
If you'd like to disable this feature, start by heading to the General menu in your iPhone's main Settings. From here, tap the Accessibility entry, then scroll down a bit and toggle the switch next to Reachability. From now on, double-tapping your home button won't cause anything to happen.
For double- and triple-click functions, there's a certain speed that these gestures need to be performed with, otherwise the multitasking interface or your accessibility shortcut won't be launched. For some people, the default speed between clicks might be too fast.
If you'd like to change this, head to the same Accessibility menu in Settings under General. From here, scroll down a bit, then select the Home Button option. Next, set the Click Speed to either Slow or Slowest, and from now on, you can take a little more time between button presses when launching double- and triple-click gestures.
If you've ever felt your iPhone buzz while it was in your pocket, chances are, that was Siri being butt-activated by accident. All it takes is a long-press of the home button to get her going, but you can stop that from happening with the right setting.
To prevent accidental Siri activation, go to Touch ID & Passcode (or just Passcode) in your Settings menu, then input your passcode to continue. Once in, scroll down and toggle off Siri under Allow Access When Locked. (This will also disable Voice Dial controls.)
Don't find Siri all that useful? You can disable her altogether—not just on the lock screen. Just note that this will NOT help you when accidentally long-pressing the home button in your pocket, because Siri's backup, Voice Control, will activate instead, and there's no way to disable Voice Control.
If you still want to disable Siri altogether and use Voice Control instead, head to the General menu in Settings, then select the Siri option. (In iOS 10, Siri has its own menu in the Settings menu, so you don't have to go to General first.) From here, turn the feature off using the switch at the top of the screen, then press "Turn Off Siri" when prompted.
Up until this point, I've only covered tips that involve removing or slowing down home button functionality for the sake of simplifying things. But you can actually add functionality to this button by assigning a triple-click gesture. Unlike Siri and Reachability, it's quite hard to trigger accidentally, so it's something you may want to consider.
Head to the Accessibility menu in Settings again, then scroll down to the bottom and select Accessibility Shortcut. From here, select any of the available options, and from now on, that action will be triggered when you click your home button three times in rapid succession.
This even works with multiple accessibility shortcuts enabled, in which case you'll be prompted to choose an action after triple-clicking.