If you have an Apple Watch Ultra, you've probably already noticed that extra button on the left side: the famous action button. It lets you launch functions instantly, and if you set it up right, it'll save you a lot of taps and scrolling on your watch. Personalizing it is key to taking advantage of your routines and emergencies, and here we tell you how to do it easily and without missing any relevant settings.
In this guide, you'll learn how to choose what that button does when you press it, how to use Quick Selector to toggle actions on the fly, and how to turn the security siren on or off. We'll also review how it fits with the Digital Crown and side button., including the behavior of watchOS 9 and earlier versions. The information you'll see is based on official documentation and content updated as of the end of September 2025, so the tour will be comprehensive and, above all, practical.
What the Apple Watch Ultra action button does
The action button is exclusive to Apple Watch Ultra models and is located on the left side of the case. Its purpose is to give you immediate access to a specific function or set of actions of your choice. You can customize it to open your favorite tools with a single click., which is extremely convenient during training, sailing or everyday tasks where every second counts.
In addition to the standard press, the action button supports a long press that you can use for emergency situations. With a long press you can activate the siren, open your medical record, use Compass Return or initiate an SOS Emergency call., depending on how you have it configured. These options are intended for personal safety and orientation in environments where you need to be located or retrace your steps.
The siren on your Apple Watch Ultra is especially useful if you're lost or need to call for help from a distance. For more details on how to use it, learn how to activate the emergency siren on your Apple Watch. When active, simply press and hold the action button for a few seconds to play a repeating sound pattern. The sound can be heard up to 600 meters away. in suitable conditions, making it an interesting tool for mountain activities, night outings or any outdoor incident.
Another advantage of the action button is quick access to your favorite functions. You can configure it to start workouts, mark a point, open the compass, turn on the flashlight, launch a specific app, or, if you find it more versatile, display a Quick Selector that lets you choose between multiple shortcuts instantlyAll this without wasting time navigating menus or searching for small icons on the screen.
As a complement to that button, remember that the Apple Watch is operated with taps, turns, and gestures. Touch gestures coexist with the Digital Crown and the side button, and the purpose of the action button is to add to that mix to speed up what you do most often, not to completely replace other controls on your watch.
Digital Crown and side button: How they fit with the action button
To fully understand the role of the action button, it's helpful to understand what each physical control on the Apple Watch does and how to use all the buttons and gestures on your Apple Watch. The Digital Crown is primarily used for navigation and opening apps, while the side button provides quick access to the Dock or Control Center, as well as security and payment options. The action button joins these two controls to offer an ultra-fast and configurable shortcut..
Regarding the Digital Crown, its overall functionality is simple and very useful. Turning it scrolls through lists, screens, and complications, and pressing it takes you to the app view or back to the watch face, among other functions. In watchOS 9 and earlier versions, the logic of pressing or turning the crown is maintained. to navigate precisely through the system, relying on touch gestures when you need to.
The side button varies slightly depending on the version of watchOS, but its key uses are well defined. On some models or versions, a press shows or hides the Dock, while on others it opens or closes Control Center.; This difference is normal and depends on the system you have installed.
- Short press: Depending on the watchOS version, shows/hides the Dock or Control Center.
- Hold down: Activate Emergency SOS to call for help quickly.
- Double click: Open Apple Pay to pay without taking out your iPhone or card.
- Additional long press: allows you to turn the clock on or off when necessary.
This same side button functionality is sometimes described with different verbs, such as “press” or “tap,” but the result is the same. Tap/long press for Dock or Control Center, long press for SOS, double-click for Apple Pay, and long press to power on or off.; with this you cover 100% of what you need on a daily basis.
The general idea is that the side button and Digital Crown remain your navigation controls and system utilities, while the action button remains for whatever you decide to prioritize. This separation of roles prevents conflicts and allows you to act faster., for example, starting a workout or marking a waypoint with a single dedicated press.
How to customize the step-by-step action button on the watch itself
The entire process can be done conveniently from the Apple Watch Ultra, without having to open anything on the iPhone. You'll just need to locate the "Action Button" setting, choose the primary action, and adjust the press and hold behavior. (including the siren). If you prefer, you can also set up a Quick Selector to decide on the fly.
1. Go to Settings and search for “Action Button”
Start by pressing the Digital Crown to open the app view, where you'll see the Settings icon. Tap it to enter and scroll to the section labeled "Action Button." The route is: Digital Crown → Settings → Action Button, and on that screen you will find all the necessary options.
If you're using the app grid, you may find it faster to type or dictate "Action Button" into the Settings search box to jump right in. The key is to get to that main settings panel, since from there you can adjust both the single and long press.
2. Choose what the first press does
Under "Action Button," tap the "Action" section to define what happens when the button is pressed once. You'll see a list of available options to associate with that initial press. Select the setting you use most (for example, open a mode, app, or tool) and confirm the choice.
When you're done, use the arrow to go back if you need to change sections, and tap "First Tap" to review the specific parameters for that first tap. Follow the on-screen prompts to fine-tune the details. (for example, choosing a sub-function within the action you have assigned) and return with the arrow whenever you want.
If you later decide you prefer a more flexible approach, you can set Quick Selector as your primary action. This way, pressing the button will open a selector to choose between several actions without going into Settings., which is very practical if you change activities frequently.
3. Turn the siren on or off by holding down
In the same "Action Button" section, you'll see the control to enable or disable the siren when you press and hold it. Look for the toggle next to the "Press and hold to activate" option and adjust it to your liking. When this feature is enabled, a long press of the action button will trigger the siren., emitting a continuous and very striking acoustic warning.
The Apple Watch Ultra siren is designed for emergency situations, with a tone that can be heard from a distance. Under favorable conditions, the warning can be heard up to 600 meters away., making it a very useful security tool in open environments. Use it responsibly and remember that once activated, the watch will continue broadcasting until you manually stop it.
4. Customize (or disable) the Quick Selector
If you like having multiple options at your fingertips, press and hold the action button to open the Quick Selector and choose one of the available actions in that panel. This switch allows you to switch between functions without going into Settings, ideal for those who frequently alternate between training, sailing and other tasks.
To define what appears in that menu, go back to Settings → Action Button and tap "Quick Switch." From there, you can select the actions you want to appear in the switcher and reorder them if necessary. You also have the option to completely disable Quick Selector. If you prefer the button to always go to the same fixed action without showing any previous list.
Once you're familiar with these options, it's worth spending a few minutes trying out different configurations. Think about what you do most often and adjust the main action to that routine; if that changes depending on the day, Quick Selector will give you the flexibility you need without having to constantly return to Settings.
Also, remember that the action button coexists with the rest of the Apple Watch controls and gestures. All the familiar functions are still there: turn the Digital Crown to scroll, tap to interact, and use the side button as a system utility hub. The value of the action button is in saving steps and in the immediate reaction when you need to execute something safely and without margin of error.
As an important detail, the action button is on the left side of the Apple Watch Ultra, making it easy to access with your other hand even when wearing gloves or while exercising. The placement is designed to minimize accidental touches and give you a firm press., something that is crucial if you are going to use it for emergencies or navigation with a compass.
A good practice is to review your settings from time to time to make sure the assigned action still fits with your current habits. If you've been training more outdoors lately, you might want to set Compass Return to the first tap; if you're more into the gym, set it to the start of workouts. The key is to adapt the button to your daily life and not the other way around., also taking advantage of the Quick Selector when it suits you.
Finally, don't forget the safety aspect. If you keep the siren active by long-pressing, avoid leaning on the button for extended periods of time when wearing the watch too tightly or in awkward positions. Learning the exact pressure and the correct duration will save you from unintentional activations. and will ensure that when you really need it, you can use the feature without hesitation.
Once you've fully understood the role of the action button, how it relates to the Digital Crown and side button, and how to configure Quick Select and the siren, you'll be ready to use your Apple Watch Ultra with confidence. Mastering these three physical controls and customizing them will allow you to act quickly, stay safe, and move around the system with ease., whether during a demanding workout, a route through the countryside or in the hustle and bustle of everyday urban life.
