但既然还是测试版本，系统的稳定性肯定会有所欠缺，又或者体验后发现自己还没能习惯「液态玻璃」的全新风格。 想吃「后悔药」，回到以前的稳定版本，该怎么办？ 写在前面：本文仅供参考。用户进行任何系统操作需谨慎处理，如遇到困难请咨询苹果官方。 作为全面换新颜的一代，想必不少小伙伴已经迫不及待更新了 iOS 26、iPadOS 26 甚至 macOS 26 的测试版进行尝鲜。 升级很简单，只要申请注册下载固件就能升级，但如果想回去，那就要花不少功夫，而且还可能会导致自己的设备数据尽数丢失。 爱范儿为大家整理好了 iPhone、iPad、Mac 和 Apple Watch 从测试版降级的教程，希望能帮到有需要的你。 如果你还没更新 iOS 26，但已经心动不已，也可以参考这篇文章，对后续降级会遇到多少麻烦心里更有数。 省流版： 数据备份好了吗？ 别着急。在降级之前，首先要确认一个重要问题： 数据提前备份好了吗？ 和升级不同，如果想要进行降级，设备是不会保留任何数据的，也就是说完成降级之后，你会获得一台被还原，完全空白的设备。 这也是为什么在升级测试版系统之前，苹果也会提醒开发者/尝鲜用户，提前做好备份。 需要注意的是：现 ...

Core Viewpoint - The article discusses the process and considerations for downgrading from the beta versions of iOS 26, iPadOS 26, and macOS 26 back to previous stable versions, emphasizing the importance of data backup before upgrading to beta versions [1][2][20]. Group 1: Downgrade Process - Downgrading from beta versions requires significant effort and may result in data loss, as devices will be restored to factory settings [5][12]. - Users must ensure that they have backed up their data before attempting to downgrade, as the downgrade process does not retain any data [8][10]. - For iPhone and iPad, the downgrade process involves connecting the device to a PC or Mac, entering recovery mode, and downloading the appropriate firmware [9][21]. Group 2: Backup Methods - iPhone and iPad can be backed up using either a computer for full backups or iCloud for cloud backups, with the latter typically being enabled by default [13]. - Mac users should utilize "Time Machine" for backing up data before upgrading to macOS 26 [13]. - Apple Watch backups are automatically included in the iPhone backup, and users should ensure their iPhone is backed up to retain Apple Watch data [15]. Group 3: Downgrade Limitations - Downgrading is only possible while Apple is still signing the older firmware versions, which typically lasts for about a month after a new version is released [29][30]. - Users cannot downgrade to a version for which Apple has stopped signing, making it crucial to check the signing status of firmware [32][33]. Group 4: Special Considerations for Devices - The downgrade process for Mac is slightly more complex but manageable for users following the outlined steps [34]. - Apple Watch downgrades cannot be performed by users at home and must be done through official channels, such as visiting an Apple Store [45][46].