The AirPort Time Capsule was a unique product since it was both a Wi-Fi router and a network attached storage (NAS) device. (Briefly, a NAS is a hard drive that is available to all Macs on your Wi-Fi network.) Conveniently, you can use either or both of these features. In other words, you could use both of these features together or the Wi-Fi router feature or network attached hard drive feature independently. If you only use only the Wi-Fi router feature, then read my article about replacing your AirPort. If you use your Time Capsule as only a backup device, or as both a router and backup device then consider the following options.
This article only gives you an overview of the options available to you. Setting up any of these options can be tricky. Nobody likes to have interruptions to their Wi-Fi network or their backup systems so please consider hiring a quality, local Apple consultant, as needed.
Options 1-3 are appropriate if you Time Capsule only as a Time Machine backup destination.
Options 4 and 5 are appropriate if you use your Time Capsule as both a Time Machine backup destination and as a wireless router.
Option 1 – Use The Time Machine Destination Feature in File Sharing
This option requires you to connect an appropriately sized external hard drive to your Mac, then use the Time Machine Destination feature that Apple includes in macOS 10.13 High Sierra (and newer) to setup a shared folder on your external hard drive. You could either buy a multi-terabyte hard drive or even a dual hard drive system that would let you setup a a RAID 1 mirror.
This option makes the most sense if you have a Mac that is stationary, such as an iMac or a Mac mini. If all of the Macs on your network are laptops, which come and go, then this isn’t an appropriate option since the external hard drive needs to be connected to one chosen Mac. If that Mac leaves the network then your entire backup system stops working. If you only have laptops, consider Option 3.
Option 2 – Buy Retrospect Desktop
This option isn’t an exact replacement, but I list it here, nonetheless. Retrospect has been around for over 30 years and was once the predominant backup solution for individual Mac owners and Mac-based businesses. Retrospect is an alternative to or competitor of Time Machine, so you would stop using Time Machine and use Retrospect instead. Retrospect is available with many license variations. It can scale from being used to backup just 1 Mac, 1 Mac server or multiple servers and numerous Macs and PCs across your home or business network. Retrospect can backup to a local hard drive, a NAS, a cloud-based backup service, or a combination of all of these options. Retrospect is a great option if you need to backup both Macs and PCs across a network.
Option 3 – Buy a Synology NAS
You could buy a Synology Network Attached Storage (NAS) device and set it up as a Time Machine backup destination. The company offers a NAS selector tool that can help you to wade through the large number of NAS models.
This is a great option if you also want to use some of the other features that are available in Synology’s NAS manager DiskStation Manager (DSM), such as a private cloud storage service, video-surveillance storage, file sharing, VPN, etc.
Synology is the type of NAS that I use and recommend, but there are other NAS manufacturers on the market. The New York Times’ gear and gadget reviewers at Wirecutter offer some NAS recommendations.
Option 4 and 5 are appropriate if you use your Time Capsule as both a Time Machine backup destination and as a wireless router.
Option 4 – Buy a Synology Wi-Fi Router and Connect a Hard Drive to it
Buy a Synology RT2600ac wireless router and connect an appropriately sized hard drive to it, such as any of the drives listed in Option 1.
This is a great option is you want to take advantage of some of the other features that are available in Synology Router Manager (SRM) such as traffic monitoring, VPN, parental controls.
Option 5 – Buy one or more Eero Pros and a Synology NAS
Replace the Time Capsule’s Wi-Fi router functionality by buying an Eero Pro. Then replace the Time Machine backup storage functionality by buying a Synology NAS, as described in Option 3, and plug it into one of the ethernet ports on your Eero Pro.