It is possible to lose data when upgrading to any new version of Android. To ensure that you do not lose any data when upgrading to Android 12, it is important to back up your data before upgrading. You can back up your data either by using a third-party app or by syncing your data to your Google account. Additionally, you should make sure that your device is fully charged and connected to a reliable Wi-Fi connection before attempting to upgrade. Finally, it is important to read the release notes for Android 12 carefully to ensure that your device is compatible with the new version.