Sync Types Explained

Syncing Mac-to-mac or Mac-to-mobile is done via our Sync plugin (see DEVONthink’s Preferences > Sync or DEVONthink To Go’s Settings > Sync: Locations).

Sync is simple but you need to choose the type of sync method to use.

We suggest using a remote sync option when it is needed, not merely because the option is available. For example, you may have an iMac at home and an iMac at work. It would be impractical to move one machine to be able to sync. Or you may have a colleague, assistant, or significant other accessing a device while you’re away. However, you should still consider whether quick updates are needed in this situation.

Any remote sync location has inherent weaknesses due to:

  • Network conditions - local and remote
  • Remote server reachability and response times
  • Maximum concurrent connection limitations imposed by the service
  • Bandwidth throttling measures employed by cloud services

These are limitations sync cannot overcome, any more than your web browser can.

For the optimal experience, you should use a remote sync option when you need to. Just having a Dropbox, iCloud, etc. account does not make it an optimal solution for all situations.
This doesn’t mean you can’t successfully use a remote solution. It just means there are some stumbling blocks that can occur when using them - blocks caused by the conditions mentioned, not our sync engine - and they can inhibit proper syncing.

Mac to Mac:

  1. Bonjour (Direct Connection) Syncing between two Macs that are on the same local network that are On and running DEVONthink with the particular Syncing database(s) open.
    Note: Public and corporate WiFi often disallow Bonjour connections. This is controlled by the network administrators, not DEVONtechnologies.
    Note 2: If you have a firewall On or an application like Little Snitch monitoring your network, you must put in exceptions to allow DEVONthink’s network traffic.

  2. Local Sync Store. This is a file that can reside on a commonly accessible location, like a drive on your network. It can also be stored on a connected external drive or thumb drive. This does not require Machine A to be running for Machine B to sync.
    NOTE: While neither Google Drive nor OneDrive is specifically supported, you can use a local sync store in your local Google Drive or OneDrive folder.

  3. Dropbox Sync location This creates a remote sync store in a private folder on the Dropbox servers.
    NOTE: This is NOT the same as “putting my database in my Dropbox folder”, which you should never do.

  4. iCloud (Legacy). Using Apple’s servers as a storage location, this is a two-stage sync, writing to the local machine quickly, then iCloud itself transfers the data to Apple’s servers and between machines. This requires DEVONthink 3.x and DEVONthink To Go 2.6 or later.

  5. iCloud (CloudKit). Another iCloud mechanism but, similar to Dropbox syncing, it’s a single-stage sync, writing directly to Apple’s servers. This requires DEVONthink 3.6.2 or later and DEVONthink To Go 3.x or later.

  6. WebDAV server (such as macOS Server, ownCloud, some NAS drives) or a WebDAV-enabled cloud service (like CloudMe). Like the Dropbox option, a remote sync store is created on the server.

Mac to Mobile:

If you intend to sync with DEVONthink To Go on an iOS device, option 2 cannot be used.

Sync Matrix

Here is a simple matrix with things to consider when choosing a sync method…

Works with DTTG Pros Cons
Bonjour Yes • Fast, private, generally reliable
• Direct machine-to-machine syncing with no intermediary
• Requires devices to be on and our app(s) to be running
• Only works on LANs permitting Bonjour or non-standard port traffic. Does not work over VPNs.
• Firewalls must allow exceptions for DEVONthink traffic
Local Sync Store No • Very fast and private
• Can be located on an external drive or a shared resource, like an NAS
• Doesn’t require other Macs to be on. They can sync when they’re on and running DEVONthink.
Only for Mac-to-Mac syncing
• Requires access to the volume or machine where the sync store is locaterd.
Dropbox Yes • Generally reliable
• Direct sync with Dropbox servers
• Any cloud service can have slow/unresponsive servers, limit maximum connections, and throttle bandwidth.
• Questions of privacy, but can be offset using an encryption key.
iCloud (Legacy) Yes • Generally reliable
• Easy set up
• This is a two-stage sync: syncing locally first then iCloud does its own syncing.
• iCloud can stall (which is beyond our control or detection).
See Dropbox Cons.
iCloud (CloudKit) Yes • Generally reliable
• Easy set up
• This is a single stage sync, writing to Apple’s servers.
• There may be some throttling from Apple’s servers, so the initial sync should be done one database at a time.
See Dropbox Cons.
WebDAV Yes • With public servers, may make other cloud services available to syncing
• When hosted locally, provides a fast, generally reliable, and private sync. This is especially true on Ethernet.
• The reliability of a local setup may vary.
• Local servers / NAS devices may require more technical expertise to set up.
• If using a public cloud service, see Dropbox Cons.

Sync is covered in the built-in Help > Documentation > In & Out > Sync or the manual.
Sync for DEVONthink To Go is covered in its built-in Help > Sync your databases or its manual.


This little clip is old but the concept still holds true.

I’ll look into doing an update soon :slight_smile: