We get it. You've opened Cozi, added a dentist appointment on your phone, and your partner's screen still shows Tuesday as empty. Or worse — events have vanished entirely.

"Cozi not syncing" is one of the most common complaints about the app, and it's been that way for years. If you're here, you're probably mid-frustration. So let's start with what actually works before we talk about why this keeps happening.

Quick fixes that genuinely help

Before anything else, try these in order:

1. Force close and reopen

On iPhone: Swipe up from the bottom, find Cozi, and swipe it away. On Android: Settings → Apps → Cozi → Force Stop. Reopen. This clears a stuck sync process and resolves the issue about 40% of the time.

2. Check your internet connection

Cozi syncs over the internet — it has no offline mode. If you added events on the Tube or in a school with patchy WiFi, they're sitting in a local queue. Connect to solid WiFi and reopen the app.

3. Pull down to refresh

On the calendar screen, pull down firmly. Cozi doesn't sync in the background on most devices — it only checks the server when you actively use the app or pull to refresh.

4. Check your login

Both you and your partner must be logged into the same Cozi account. This sounds obvious, but it's the number-one cause of "my partner can't see my events." Go to Settings → Account and confirm the email address matches on both devices.

5. Update the app

Open your app store, search for Cozi, and hit Update if available. Older versions have known sync bugs that have been patched.

6. Reinstall

Delete Cozi, reinstall it, and log back in. Your data lives on Cozi's servers — reinstalling just gives you a fresh local copy that re-syncs from scratch.

7. Check permissions

On Android, go to Settings → Apps → Cozi → Battery and make sure it's not set to "Restricted." Android's battery optimisation aggressively kills background processes for apps it deems non-essential.

Why Cozi keeps having sync issues

Here's what's actually going on under the hood.

Cozi doesn't sync in real-time. Unlike Google Calendar or Apple Calendar, which push updates instantly, Cozi uses a polling model. The app checks the server at intervals — and those intervals can be long, especially if the app hasn't been opened recently.

No background sync on most devices. Modern operating systems restrict background activity to save battery. Cozi hasn't invested in the push notification infrastructure that would let it sync silently. So if neither person has opened the app, nothing updates.

Partner conflicts. If two people edit the same event at roughly the same time, Cozi doesn't always merge gracefully. One person's change can overwrite the other's — or the event can appear to vanish before reappearing hours later.

Aging infrastructure. Cozi launched in 2005. That's over two decades ago. The sync architecture was designed for a different era of mobile connectivity. While the app has been maintained, the core sync engine hasn't had a fundamental rebuild.

None of this makes Cozi a bad app — it's free, it's simple, and millions of families use it happily. But if you're relying on it for time-sensitive school events and finding that dates aren't reaching your partner, you're not imagining things.

When the problem isn't fixable

If you've tried everything above and events still don't appear reliably on both devices, there are a few structural limitations you can't work around:

Cozi has no native calendar export. You can't push Cozi events to Google Calendar or Apple Calendar in real-time. There's a feed URL you can subscribe to, but it's read-only and updates slowly.
No email scanning. Every school event still needs to be typed in manually — and if only one parent does it, sync issues feel worse because the other parent has no backup source.
No proactive reminders. Cozi sends a daily agenda email, but doesn't ping you days before an important date.

If the manual entry plus unreliable sync is the combination that's breaking things for you, it might be worth looking at what else exists now.

What some parents switch to

We built Nuet specifically for parents who were tired of manually entering school events into shared calendars. It connects to your email inbox directly and extracts school events from ParentMail, Arbor, School Gateway, and similar platforms — without forwarding, copy-pasting, or typing anything in.

It won't fix Cozi's sync issues, because it's a different approach entirely: instead of a shared calendar you both type into, it's an inbox monitor that puts events into your existing Google or Apple Calendar automatically.

That's not for everyone — if you love Cozi's lists and recipes, Nuet doesn't do those things. But if the calendar sync was the part driving you mad, it's worth a look.

Compare Nuet vs Cozi in detail →

FAQ

Why does Cozi take so long to sync between devices? Cozi uses a polling model rather than real-time push updates. The app only checks for new data when you open it or pull to refresh — it doesn't sync continuously in the background like Google Calendar or Apple Calendar.

Can I fix Cozi sync issues permanently? The troubleshooting steps above (force close, check login, reinstall) resolve most one-off issues. However, the underlying polling-based sync architecture means delays between devices are a structural limitation of how Cozi works, not a bug that can be patched on your end.

Does Cozi sync with Google Calendar or Apple Calendar? Cozi offers a read-only calendar feed URL you can subscribe to in other calendar apps. However, it updates slowly, doesn't sync in real-time, and is one-directional — changes in Google or Apple Calendar won't appear in Cozi.

Is there an alternative to Cozi that syncs automatically? If your main frustration is school events not reaching your shared calendar reliably, apps like Nuet take a different approach — monitoring your inbox for school emails and adding events to your Google or Apple Calendar directly, removing the manual entry step entirely.