There are a few reasons you'd need to factory reset an Apple Watch Series 9, and the method you use depends on whether you're selling it, passing it on, or stuck with a frozen screen. The Series 9 runs watchOS 26 and pairs with an iPhone XS or later running iOS 26. All the steps below reflect that specific software and hardware combo.
Force restart the Series 9 if it goes unresponsive
If the watch is stuck on an app, the screen is black, or it's frozen on the Apple logo, a force restart is the first thing to try. This isn't a factory reset, it's a hard reboot, and you won't lose any data.
Press and hold the side button and the Digital Crown at the same time for at least 10 seconds. Release both buttons when you see the Apple logo. The watch takes about 30 seconds to boot back up to the watch face. In my experience, this clears most software hiccups without needing a full wipe.
Erase all content and settings directly on the watch
If you want a clean slate right from the wrist, go to Settings > General > Reset > Erase All Content and Settings. You'll need to enter your passcode to confirm. Be warned that this wipes out your apps, data, watch faces, and Apple Pay cards.
One thing I like about this method is it doesn't require the paired iPhone to be nearby. However, it doesn't automatically remove Activation Lock. You'll still need to remove the watch from your Apple ID in Find My or the Watch app later, or the new owner could get stuck.
Unpair from the Watch app for a clean break
If your Series 9 is still linked to your iPhone and working (even if slow), unpairing from the Watch app is the cleanest method. Open the Watch app on your iPhone, tap your watch name at the top, then tap the info icon (the lowercase i). Choose Unpair Apple Watch and enter your Apple ID password to disable Activation Lock.
This process automatically creates a complete backup of your watch before erasing it. That backup includes your watch faces, app layouts, and health data. It also removes your cellular plan, which is handy since watchOS 26 has known pairing issues with some MVNO carriers after IMEI changes.
The erasing itself takes about 5 to 10 minutes. You'll see progress on the iPhone screen. After it finishes, the watch restarts to the pairing animation and is ready for a new owner or a fresh start.
Push a restore from the Watch app if it won't boot
If the Series 9 is stuck in a boot loop or won't get past the Apple logo even after a force restart, try a forced restore from the Watch app. Place the watch on its magnetic charging puck and bring your iPhone within range. Open the Watch app, tap your watch name, tap the info icon, and select Restore Apple Watch.
This downloads watchOS 26 and reflashes the watch. I'd set aside about an hour for this, as the download and install can take 30 to 90 minutes depending on your Wi-Fi speed. If the restore fails, you'd need to visit an Apple Store or send it in, since the Series 9 doesn't expose recovery mode externally for end users to manage manually.
Erase the watch remotely through Find My
If you sold your Series 9 but forgot to wipe it, or if it's lost, you can erase it remotely. Open the Find My app on your iPhone or go to iCloud.com/find. Select your watch from the device list, then choose Erase This Device.
The watch wipes itself the next time it connects to a known Wi-Fi network or a trusted iPhone. Activation Lock remains enabled, which makes the watch unusable to anyone else without your Apple ID. Once it's erased, you can remove it from your account so the buyer can pair it to their own phone.
Setting up the watch after a reset
Once the Series 9 is wiped, hold it close to your unlocked iPhone. The Watch app automatically opens a setup window. Tap Set Up Apple Watch, then scan the bubble animation with your iPhone camera.
If you unpaired from the Watch app, you'll see an option to Restore from Backup during setup. This brings back your watch faces, complications, and app layout. If you set it up as new, you'll start fresh. Either way, you can enable on-device Siri and the Double Tap gesture during setup, though Double Tap can sometimes feel unresponsive in colder weather.
After setup, check the battery health in Watch app > General > About > Maximum Capacity. The Series 9 battery tends to degrade faster than later models due to its thicker case design. Knowing the health percentage helps you decide if you need service or if the watch just needs to be charged up normally.
