04 Dec Things 3 Not Syncing Projects Across Mac and iPhone: The Background Refresh + Database Repair That Worked

Staying organized in today’s digital world is more important than ever—and for many, Things 3 by Cultured Code is the go-to app for task and project management. Its beautifully crafted UI and seamless user experience make it a favorite for both casual users and productivity enthusiasts. However, when syncing falls apart, especially between Mac and iPhone, the entire GTD (Getting Things Done) system can feel like it’s crumbling. This article dives into a real-world issue where Things 3 failed to sync projects properly and how a specific sequence involving background refresh settings and database repair finally resolved it.

TL;DR—What Worked

If you’re encountering issues with Things 3 not syncing projects between your Mac and iPhone, try this: enable background app refresh on your iPhone, make sure both devices are on the same Things Cloud account, and perform a database rebuild on both. This combination appears to clear out sync conflicts and triggers the correct behavior. While it’s not officially documented as a fix, this method has proven effective in real-world scenarios. Don’t forget to back up your data first—it could save you a lot of headaches.

The Problem: Incomplete or Nonexistent Project Sync

Everything seemed fine—until it wasn’t. For weeks, task items and individual to-dos synced seamlessly across devices. But then suddenly, entire projects went missing on the iPhone while still appearing perfectly fine on the Mac. At first, it looked like a delay. But a day later, nothing changed. A newly created project on the Mac wouldn’t appear on the iPhone at all—even after closing and reopening the app.

Initial troubleshooting yielded little:

• Wi-Fi and cellular connections were stable
• Both devices showed they were connected to Things Cloud
• No error messages or sync failure indicators appeared on either app

This scenario is frustrating because it undermines the whole purpose of using a centralized productivity platform.

Digging Deeper Into the Sync Mechanism

To understand the fix, we need to look into how Things 3 handles its internal syncing process. Things relies on Things Cloud—a sophisticated, incremental sync engine designed to minimize data traffic while keeping devices up to date near-instantaneously. The problem arises when there’s a:

• Conflict between app states or device statuses
• Corrupted local cache or database entries
• Disabled background syncing or refresh

When any of these occur, it’s possible for data (especially large objects like projects) to remain unsynced without any user notification.

The Fix That Actually Worked

After countless attempts such as reinstalling the app, logging in and out of Things Cloud, and resetting network settings—one specific sequence of steps finally made things right. Here’s a breakdown:

1. Enable Background App Refresh on iPhone

This might sound trivial, but it’s essential. Things 3 needs to periodically wake in the background to fetch updates—even if push notifications arrive. Without background refresh, it stalls and skips syncing unless manually opened and refreshed.

How to Check:

1. Go to Settings > General > Background App Refresh
2. Ensure it’s toggled on globally and specifically for Things

In the testing scenario, this setting had been inadvertently disabled, which stopped the app from updating even though it was connected to the cloud.

2. Rebuild the Things Database

Things 3 stores a local database on both Mac and iPhone. If inconsistencies arise, simply syncing won’t resolve corrupted or outdated entries. Rebuilding clears and reinitializes the structure without deleting your projects—assuming they’re saved to Things Cloud.

Steps to Rebuild on Mac:

1. Open Things 3 on Mac
2. Hold down the Option key and click the Help menu
3. Select Rebuild Database

Steps to Rebuild on iPhone:

1. Delete the app from your device
2. Reinstall it from the App Store
3. Log back into Things Cloud—it will re-download your full database cleanly

After both systems were rebuilt, synchronization resumed and the previously missing projects immediately appeared on the iPhone in full detail.

Why This Works

The combination of enabling background app refresh and cleansing local databases seems to force both devices to re-negotiate their sync status with Things Cloud. It’s not unlike a DNS flush forcing a computer to request fresh routing information rather than relying on potentially outdated local data.

This method also ensures:

• Old corrupted caches are removed
• The cloud becomes the single source of truth
• Devices re-download an up-to-date set of content

It may not be the most elegant solution, and it’s certainly not one that Cultured Code publicly recommends as a go-to fix, but it’s effective.

Things to Check Before You Begin

Before attempting these steps, consider verifying a few other elements that could interfere with syncing:

• Date & Time: Ensure automatic time-setting is enabled to avoid timestamp mismatches
• iCloud vs Things Cloud: Things doesn’t sync via iCloud. Make sure you’re logged into Things Cloud on both devices
• App Versions: Use the same version of Things 3 across your devices for best compatibility

Backing up your data is always a good idea. On Mac, go to File > Backup Database and save a local copy. While this issue rarely results in data loss, preparation is key.

What Didn’t Work

Just so you can avoid wasting time, here are a few solutions that did not solve the issue in this case:

• Manually pulling down-to-refresh repeatedly
• Turning airplane mode on/off to reset the network
• Force quitting and reopening both apps
• Logging in and out of Things Cloud repeatedly

While these might be helpful in some syncing problems, they didn’t address the root cause here—a disabled background refresh paired with a stale local database.

Final Thoughts

The syncing architecture of Things 3 is generally robust and trustworthy—but like all software, it’s not immune to hiccups. When projects stop syncing between Mac and iPhone, it’s easy to panic. However, resist the urge to nuke everything. Instead, take a methodical approach:

1. Check background app refresh settings
2. Ensure Things Cloud is connected on both devices
3. Rebuild the local databases

In this real-world scenario, these steps were the turning point after hours of fruitless troubleshooting. Whether you manage your entire life in Things or just your weekly grocery list, restoring sync stability is essential to productivity peace of mind.

By following the steps carefully, not only was the syncing problem fixed—but also trust in the workflow was restored.