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Troubleshooting OmniFocus Performance

This article has not been updated for OmniFocus 4.

Techniques to Improve Speed, Sync Times and Data Reliability

There are several factors that impact OmniFocus performance and reliability, and that slow down connectivity to the Omni Sync Server database. This article describes what can slow OmniFocus down, or make the data appear incorrect, and offers some suggestions on ways to fix it!

Support Standbys

The following four solutions sound trite sometimes — some might suggest that they are “Support Call Clichés.” What they should actually be called are, “Pieces of advice that really work!”

Please check that you have tried these solutions before continuing through the other sections of this article:

  1. Please shut down OmniFocus and try re-booting the device/machine and see if that helps!
  2. On macOS only, please shut down OmniFocus and try a Safe Mode re-boot. This starts the Mac with any non-essential elements turned off. Apple has instructions on that process here: And there is more about the Safe Mode start-up here:
  3. Occasionally, uninstalling and re-installing the software will be a solution.

    Note: Before uninstalling OmniFocus on an iOS device, be aware that this step may delete the data from the device. If this is the only local copy of the data, and if you are not syncing, you will want to check that there is a backup of the local database file (named OmniFocus.ofocus) outside of the OmniFocus folder.

  4. Double-check the amount of free space on your device:

    • On a Mac, go to  Menu > About this Mac > Storage.
    • On an iOS device, go to System Settings > General > iPhone/iPad Storage.
    • If there is very little free space left on the device, you will want to either purchase more storage space or delete some items on the device, or both!

Reduce the Database Size

Reducing the size of a large database down to about 10 MB will improve its performance — size is especially impactful with databases that sync and on iOS devices. While the storage on a device or machine may easily fit a really large database, downloading (or uploading) is a separate process, with very different demands on the device.

Usually the biggest contributors to database size are attachments. Read Finding and reducing the size of your OmniFocus database for tips on finding and removing the largest attachments, as well as other ways to reduce the size of your database, such as archiving.

Although there isn’t a size limit to how big an OmniFocus database can be, the app will start to lag and sync issues will appear when it starts to get too large.

Compact and Replace the Server Database

Once you’re done reducing the database size, you’ll want those changes (and the benefits!) to flow to the rest of your devices right away. On the machine or device where you’ve reduced the database, follow the steps below:

On macOS — for OmniFocus versions 3.8 and above

  1. Go to menu: File > Export…
  2. In the Export window, select File Format: Backup Document (OmniFocus)
  3. Click Save
  4. Find and double-click on the OmniFocus-backup.ofocus file saved in step 3
  5. Click Revert to This Backup in the upper right hand corner
  6. Click the Revert button to confirm this step
  7. Close the OmniFocus Backup window

On your other device(s), you may be asked to choose a database to keep. If so, please select to keep the server (or sync) database. On those devices, the local database will be replaced.

For OmniFocus for Mac versions prior to 3.8, please follow the instructions in the following article to compact and replace the server database: Finding and reducing the size of your OmniFocus database.

On iOS

  1. Open OmniFocus, go to the Settings screen (go to the Home page > tap the gear icon ⚙️)
  2. Scroll down to and tap Sync
  3. Tap Turn Sync Off
  4. Click the confirmation prompt Turn Sync Off
  5. Tap Settings to go back, and tap Compact (there won’t be any acknowledgement)
  6. Tap Sync and enter the account to sync, and password if prompted
  7. If the system asks questions such as “Catch up with your synced data?” and/or a reminder to migrate your data, tap Cancel
  8. Tap Replace Sync Database
  9. Confirm by tapping Replace Database

On your other device(s), you may be asked to choose a database to keep. If so, please select to keep the server (or sync) database. On those devices, the local database will be replaced.

Note on Compacting an OmniFocus Database

“Compacting” makes a database more streamlined by removing redundant transactions.

OmniFocus’ sync system is designed so that each device has a full copy of your database, including a list of any changes. The changes to your database are stored as transaction files (“zip files”) that record each change from a common historical database.

When comparing databases, the system finds the common historical database state and copies over the change files since that historical transaction to bring all the databases up to current. Compacting is the process of combining all of the “zip files” or transactions into a single transaction. That file becomes the database of record, to which any new change transactions (new zip files) are added.

A fully compacted database will have 1 zip file.

Sync All and Sync Often

Before compacting, OmniFocus waits to make sure that all copies (or registered devices) connected to the same sync account have seen all the change transactions (this is why it’s important to sync all copies of OmniFocus regularly). When one copy gets out of date, all the others have to hold onto the intermediate changes until the left-behind copy syncs again.

The more registered devices syncing to the server, and the more “behind” any device gets, the more likely that the system will be unable to compact the database, because the common historical transaction has been lost. If there is more than one device that is behind, the problem will compound. Note that there is a “registered device” for each syncing copy of OmniFocus (for instance, having OmniFocus 4 and OmniFocus 3 on the same iPhone will create two registered devices).

This is why the advice from Support Humans is “Sync All and Sync Often.”

Sometimes there might be a “ghost device” registered to sync with the database — usually a duplicate registration of an OmniFocus instance. You will want to remove these un-used copies if you notice them, as they will also impact the system’s ability to compact.

To remove an un-used copy of OmniFocus from sync registration:

On macOS

  • Open OmniFocus on your macOS computer
  • Go to menu: OmniFocus > Preferences… > Sync tab > Show Sync Details… > Devices tab
  • Select any duplicate or old registrations
  • Click Unregister, confirm by clicking Unregister again

On iOS

  • Open OmniFocus on your iOS device
  • Go to the Settings screen (go to the Home page > tap the gear icon ⚙️)
  • Scroll down to Database / Sync
  • Tap Registered Devices
  • Tap Edit
  • Select the minus sign next to each device to remove

Geographic Location

Omni Group servers are located in Seattle, WA, USA. The further away you are from them, the longer it takes for the round-trip traffic to make it from your device to the servers and back again. Using a WebDAV host that’s geographically closer to your location is an option, not to mention you can set up your own WebDAV server.

Resources for setting up your own WebDAV server

Because of the many different server configurations that can be set up, Support isn’t able to provide much help with troubleshooting non-Omni Sync Server set up and issues, but here are a few resources that can help:

Improve the Internet Connection

Internet connection speed is important to take into account. This means you can have different sync experiences between the Wi-Fi network at the office and the wispy cellular connection on the edge of town.

If you think your cellular connection is too slow to sync OmniFocus, try limiting sync to Wi-Fi through the Operating System settings in your iOS or macOS.

Sometimes, the source of a connection issue is the reliability of the network. If there is a network outage in one part of the internet path to our servers, then Omni’s Sync Server may appear to be down. In that case, it is always worth checking with the Support Humans and with your internet service provider.

Data Looks Wrong (or Time to Rebuild the Database)

If the data on the application is incorrect, or the data showing in the Project Perspective is different from the data in the Inspector, then it might be time to run a Database Rebuild (or Rebuild Database).

A Database Rebuild analyzes and consolidates all of the entries in your OmniFocus database to make sure they are consistent. It will initiate a new back up and then restore your database.

Rebuild the Database On a Mac

To rebuild the database on a Mac, please:

  1. Go to the menu > File
  2. Select Rebuild Database…
  3. Click “Rebuild” to confirm

Rebuild the Database On an iOS device

To rebuild the database on an iOS device, click this link in a browser:

Rebuild OmniFocus Database

  1. Click “Open”
  2. Click “Invoke and Quit”
Last Modified: Dec 13, 2023

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