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Synchronization fails


I was happy to learn about Todoist and became a Premium customer in a matter of hours, as this was just the tool I needed. I've now been using Todoist for about a month I would say, but again and again I've experienced synchronization issues, and this has really become a nuisance.

I'm using Todoist Web on Chrome on 2 different PC's, of which one of the PC's have 2 installations of Windows. So I have 3 Windows installations (Windows 8.1) where I use Todoist Web from. I've used the Create Program Shortcut in Chrome on all Windows installations, so I have a shortcut to Todoist.

And then I'm also using Todoist on my iPhone.

What I'm seeing, is that sometimes a task is listed twice on my iPhone. However, I've learned to just ignore that, even though it annoys me.

But I'm also seeing situations where one or more of the Windows PC's are not in sync. Usually it's the deadline information on tasks that are not in sync. I've seen it with parent tasks where I initially set a deadline, create child tasks with deadlines, and then later removed the deadline on the parent task.

But I've also seen it on normal tasks, where I've removed the deadline or changed it, and this is just not propagated to some of the other clients.

Usually I can fix the sync issue on the Windows PC's by either emptying my browser cache or logging out and logging back in. But some days later, the problem comes back again.

I'm sorry to say this, but it has come to to the point that I'm starting to lose faith in my system, which is devasting to the central point of GTD: Having a system you trust where you can record the things you need to do.

I really like Todoist for the simple user interface and the features, so I really want to keep using it. But if these sync issues are not fixed, I will not be resubscribing when my subscription ends.

I can see on this support forum that I'm not the only one experiencing these sync issues, so I would really encourage you to make it a priority, to fix these issues.

Best regards

All responses

David Trey  staff
Replied on Jun 24, 2014 - 13:37 UTC

Hello René,

We're sorry to hear that. Sync issues should not happen at all and we can't reproduce them, we also use our app every day on multiple devices and so far it all syncs seamlessly.

You've mentioned having a shortcut in your browser - please make sure that the shortcut points directly to https://todoist.com - the URL must not have anything in it than this. It will then redirect you always to the latest version of the app, but if you bookmark and URL with an older version number in it then all sorts of problems can occur.

As for tasks listed twice on the iPhone - are you referring to duplicate tasks inside projects or the fact that on a date-based view if both a parent and a sub-task meet the search criteria, you may see the sub-task below the parent and then separately?

Now, as for the sync issue in general - are you at any point using the app offline (that also includes the iOS app)? Did you ever try to completely uninstall the iOS app and see if the issue persists - this way we could at least identify the iOS app as being the cause of it. Are you using a VPN, proxy, firewall, ad-blockers etc. anything that could in any way influence your connection?

Best regards,

René Gundersen  premium
Replied on Jun 25, 2014 - 07:36 UTC

Hi David

Thank you for your reply.

Let's start with the iOS app: No, I'm not using it offline. When I'm using it, I'm either on Wifi or on 3G. However, I can't of course claim that I've never been offline due to limited connectivity. But it's not like I'm using it places where there is definitely no internet connection.

I decided to take your advice and reinstall the iOS app. But before that,when I opened it up, I had a task overdue that I had previously marked as complete on one of my PC's. Even though I opened the settings panel and pressed the Refresh icon below my login information several times, the task keeped showing as overdue.

I then removed the app from my phone and reinstalled it from the App Store. Sure enough, the task was gone when I logged back in with my Todoist account. So it would seem the problem was with the app somehow not getting the correct data from your servers or not updating my local data correctly.

As for the duplication of tasks, I'm not really sure. It might be that both the parent and child tasks are showing once, and then every child task which satisfies the search filter is showing again. However, I would say that is not very intuitive or user friendly. I can't think of any reason why a user would want the task listed twice. In my head, it sounds like a technical challenge that just needs to be solved.

Regarding the web app: I'll try and update my bookmarks to use https://todoist.com instead of https://todoist.com/app, and see if that helps.

As for the offline question: No, I'm not using Todoist offline on my PC's. I'm always using it while being connected to the internet. And no, I'm not using either VPN, proxies, firewall (Except the builtin in Windows of course) or ad-blockers. I'm using Todoist from my home, so there's also no corporate hardware between me and my internet.

It baffles me to hear that you guys have not experienced it yourself, when I see it relatively often. I understand issues like this can be hard to reproduce (I work as a software developer myself), so I'll really try to see if I can notice a pattern in these issues.

But there is an issue. Even if it's a connection issue in some way, then there is an issue, because I as a user should be told that the app is unable to sync for various reasons. That way, my trust with the app is maintained. If the app just keeps going and the user is noticing that something is not in sync, then I start to distrust the app and feel I have to keep an eye out for data that is out of sync.

I'm sorry if I seem a bit blunt, but I've made Todoist a pretty important part of my day-to-day opeations, both professionally and personally. So I'm a bit frustrated with these sync issues, and would really like them to go away. The app has been reinstalled on my phone, I've taken your advice regarding my bookmarks, and I'll keep an eye out for any patterns in these issues. I'll update this thread if I have new information to share.

Thank you for your time and help, David.

Best regards

David Trey  staff
Replied on Jun 25, 2014 - 12:12 UTC


Thank you very much for this information. This indeed never happens to us and we've tried to even use all apps connected to a router that we've been randomly switching on and off to simulate all sorts of connectivity issues, even during sync - all worked well, though.

We did manage to reproduce duplication issues on iOS though and are working on it now. We'll of course continue testing other sync problems and hope to find a clear cause of these issues and fix them.

As for seeing sub-tasks twice - the reason for this is to make sure you never miss a task. If we'd only show them under parent tasks, it would mean that if you look for "today", you would have to see parent tasks there that aren't even due today, but are displayed only so that you can search for the sub-tasks matching the actual search criteria. On the other hand, displaying them only separately would mean that you'd never know if a task is a parent.

That said, this solution allows you to see only tasks that match the query, regardless of their indent level, but at the same time have an option to check what sub-tasks does a parent have, for reference.

Best regards,

René Gundersen  premium
Replied on Jun 27, 2014 - 09:14 UTC

Okay, so today I again had a sync issue. When I opened https://todoist.com on PC A, several tasks had incorrect deadlines, tasks I did not change on any device since the last time I had logged in. I tried refreshing the page with both F5 and CTRL+F5, but the tasks kept showing the incorrect deadlines.

I then started my other PC, PC B, and opened the same address, and it did not have a sync issue. All tasks had the correct deadlines. (Both PC's are by the way on the same Wifi)

On PC A, I then logged out and back in, and everything looked as it should.

This was the first time today I logged into Todoist on any of my PC's.

Trish Putnam
Replied on Jun 27, 2014 - 16:38 UTC

I've found that I will generally see similar sync issues if I haven't logged out of Todoist, and my computer goes to sleep for the night (I don't know if it happens with shorter sleep sessions, but every time I've seen it the computer has slept at least 10 hours).

Brendon Wadey  staff
Replied on Jun 27, 2014 - 16:56 UTC


When you open Todoist, how long do you wait before you try to sync/refresh it? As it can take some time to update its information. I have been testing and on a system not being isued, when logged in it will show old information, about 2 to 5 seconds it will update itself.


René Gundersen  premium
Replied on Jul 02, 2014 - 13:16 UTC

Hi Brendon

Thank you for your answer. I suppose you're talking about the web application? Yes, I've tried waiting several minutes without anything happening. However, the weird thing is that the page is actually updated when it loads. It's not like it just shows the page as it were the last time I had Todoist open. It actually updates the deadline groups (Yesterday, Today etc) and what tasks are shown under which deadline group. But sometimes a task is just misplaced, and even if I jump around from page to page, like selecting Next 7 days, or selecting a specific project, and then going back to Today, the task remains there.

Also, I just had another sync issue, but this time with the iOS app. In the app, I pressed a task and then chose the task to be completed. I got the notification that the task was marked as complete, but the task remained in the list for Today. I tried changing the view by selecting Next 7 days, but it was also on that list. I then changed back to Today, and the task was also there.

At the same time, I was also logged into Todoist on my PC, and without me doing anything on the PC, the task had disappeared from the list (Today) as it should. Here, I also tried changing the view (Next 7 days, Today etc) but the task was nowhere to be seen, as expected. I then chose to see the tasks that I had completed, and the task was there, marked as completed, as it should. But still at this moment, the task is on my lists on my iPhone, even though I've pressed sync and scrolled to the top to refresh the list. It just remains there.

Very frustrating.

Brendon Wadey  staff
Replied on Jul 02, 2014 - 14:04 UTC


Very sorry to hear this. We are looking into sync issues but as we have said its been hard to 100% reproduce. We have many reports of sync/duplication issues on iOS and we believe that these iOS issues are causing the problems on each platform.

We hope to resolve the iOS issues soon, but to confirm, have you always been using an iOS device, how often do you use it? It may seem like the issue is not related to iOS, and that is possible, but so far it would appear to be the closest thing we have to a resolution.


René Gundersen  premium
Replied on Jul 21, 2014 - 14:24 UTC

Hi Brendon

Thank you for your reply. I'm sorry I haven't replied until now, but actually that's because I haven't had a sync issue since my last post. So I haven't really thought much about this thread, which is a good thing I guess. I'm not exactly sure what has caused the issue to disappear, but I can think of 2 possible reasons:

1. Changed habit. There's frequently an update to the web app when I open todoist.com/app, which is indicated by the green gear icon. Previously, when I opened the web app and saw the green icon, I immediately clicked it and then clicked "Update". The web app then refreshed to load the new version.
I don't do this any more. I leave it alone and let it update the next time I open the app.

2. I installed an update to the iOS app some weeks ago. (Can't remember when exactly)

Maybe the issue is related to the iOS app as you also mentioned, and the latest update got rid of the bug. Or maybe there's a bug somewhere that manifests itself under certain conditions when you manually update the web app?

Regarding your question about how often I use the iOS app: I use it almost daily to see my tasks, create new ones and update existing tasks with new deadlines or marking them as complete. So I use it quite a bit, sometimes several times a day.

I'm quite happy that I haven't had a sync issue for some time now. I hope the problem has gone away for good. But if not, I'll be back in this thread. ;-)

Thank you both, David and Bendon, for your help and support.

Best regards