Unlike your iPhone or iPad, your Apple Watch doesn't have a lot of space for apps, music, podcasts, and all the other content you might try to store on it. The amount of storage varies from series to series. The Apple Watch Series 5 offers 32GB of space, but there is only 16GB on the Series 4. The Series 3 has 16GB for GPS + Cellular but only 8GB for the GPS model.
Depending on your watch version and how much content you download or sync, you could easily run low on space before you know it. But your watch can clue you in on how much space you have in total and how much is available. It can also show you how much space is used by specific apps and content, so you know what to jettison when you're running close to empty.
Check Storage Space in Watch App
Check Storage Space on Apple Watch
Remove Apps From Watch App
Now you know which content is taking up the most amount of space, you can remove items you no longer need or want. First, let's look at deleting apps using the Watch app on your phone. Open the app and swipe down the My Watch screen until you reach the section for Installed on Apple Watch. Tap the name of an app you want to remove.
Turn off the Show App on Apple Watch switch, and the app will be deleted from the watch. Return to the previous screen, and the app now appears in the section for Available Apps, where you can always reinstall it on your watch by tapping the Install button.
Delete Apps on Apple Watch
To remove an app directly from the watch, press the Digital Crown to move to the Home screen with all your apps in view. If the Home screen is in Grid View, lightly press down on any icon until they all start to shake.
Tap the X button on the app you wish to remove. At the confirmation screen, tap the entry to Delete App. Press the Digital Crown to turn off the icon jiggling.
If the Home screen is in List View, swipe through the list until you see the app you wish to delete. Swipe the app's entry to the left. Tap the trash can icon. Then tap the entry to Delete App.
Remove Music From Watch App
You may also want to delete other content from your Apple Watch, like music. Do this by opening the Watch app on your iPhone. Swipe down the My Watch section and tap the entry for Music, where you can remove songs a few different ways.
There is an option called Heavy Rotation, which can be enabled to download the albums and playlists you play. If you don't need this, or just want to see how much space you can free up, turn this switch off to remove recent albums. Next, tap the Edit link in the upper right. Tap the Delete icon next to any playlist or album, then tap the Delete button.
Delete Music on Apple Watch
To delete albums directly from your Apple Watch, open the Music app on your watch. Swipe down on each album thumbnail until you see the entries for On iPhone and Library. Tap Library > Albums and swipe down the screen until you see an album you wish to remove.
Swipe the album name to the left and then tap the ellipsis icon. At the action screen, tap the Remove button. The app asks if you want to delete the album from your library or remove this download from the watch. Tap Remove Download and the album is removed from your watch.
Resync Photos From Watch App
You can also change and limit the photos that are synced from your phone to your watch. Open the Watch app on your iPhone, then swipe down the My Watch section and tap the entry for Photos. Whether the option is set to Mirror my iPhone or Custom, you can change the album that gets synced and control the number of photos.
Tap the entry for Synced Album and switch it to a different album, maybe one that contains fewer photos. Tap the entry for Photos Limit and lower the number of synced photos to as few as 25. Your watch will then update the synced photos.
Remove Audiobooks
If you're storing audiobooks on your watch, these can be removed within the Watch app on your iPhone. In the My Watch section, tap the entry for Audiobooks. Here, you have a couple of options.
If the switches for Reading Now and Want to Read are enabled, it means your watch is automatically downloading audiobooks to fill space. Turn them off to stop the sync and make room on your device. Look through the list of synced audiobooks to find any you no longer need on your watch. Swipe one to the left and tap the Delete button.
Remove Podcasts
If you like podcasts, you can listen to them on your Apple Watch, but if you're storing them on the device, they can be removed from the Watch app. Tap the Podcasts entry on the My Watch page. There are two options available that automatically download episodes, but you can take control of them if you’re pressed for space.
The Listen Now option downloads one episode from your top 10 podcasts, while Custom adds three episodes from every show you select. The Custom option gives you more control over the synced episodes, so you may want to try that one. In that case, turn off the switch for any podcasts that you don't need on your watch.